Android 框架：快速开发中Util常用工具类总结
一、日志工具类 L.java
public class L {
private L()
{
/* 不可被实例化 */
throw new UnsupportedOperationException("Cannot be instantiated!");
}
// 是否需要打印bug，可以在application的onCreate函数里面初始化
public static boolean isDebug = true;
private static final String TAG = "DefaultTag";
// 下面四个是默认tag的函数
public static void i(String msg)
{
if (isDebug)
Log.i(TAG, msg);
}
public static void d(String msg)
{
if (isDebug)
Log.d(TAG, msg);
}
public static void e(String msg)
{
if (isDebug)
Log.e(TAG, msg);
}
public static void v(String msg)
{
if (isDebug)
Log.v(TAG, msg);
}
// 下面是传入自定义tag的函数
public static void i(String tag, String msg)
{
if (isDebug)
Log.i(tag, msg);
}
public static void d(String tag, String msg)
{
if (isDebug)
Log.i(tag, msg);
}
public static void e(String tag, String msg)
{
if (isDebug)
Log.i(tag, msg);
}
public static void v(String tag, String msg)
{
if (isDebug)
Log.i(tag, msg);
}
} 网上也有很多提供把日志记录到SDCard上的，根据需求使用。
二、Toast统一管理类 T.java
public class T {
private T()
{
/* cannot be instantiated */
throw new UnsupportedOperationException("cannot be instantiated");
}
public static boolean isShow = true;
/** * 短时间显示Toast */
public static void showShort(Context context, CharSequence message)
{
if (isShow)
Toast.makeText(context, message, Toast.LENGTH_SHORT).show();
}
/** * 短时间显示Toast * @param message 要显示的字符串资源的id */
public static void showShort(Context context, int message)
{
if (isShow)
Toast.makeText(context, message, Toast.LENGTH_SHORT).show();
}
/** * 长时间显示Toast */
public static void showLong(Context context, CharSequence message)
{
if (isShow)
Toast.makeText(context, message, Toast.LENGTH_LONG).show();
}
/** * 长时间显示Toast */
public static void showLong(Context context, int message)
{
if (isShow)
Toast.makeText(context, message, Toast.LENGTH_LONG).show();
}
/** * 自定义显示Toast时间 */
public static void show(Context context, CharSequence message, int duration)
{
if (isShow)
Toast.makeText(context, message, duration).show();
}
/** * 自定义显示Toast时间 */
public static void show(Context context, int message, int duration)
{
if (isShow)
Toast.makeText(context, message, duration).show();
}
} 三、SharedPreferences封装类 SPUtils.java 和 PreferencesUtils.java
1. SPUtils.java
public class SPUtils {
/** * 保存在手机里面的文件名 */
public static final String FILE_NAME = "share_data";
/** * 保存数据的方法，我们需要拿到保存数据的具体类型，然后根据类型调用不同的保存方法 * * @param context * @param key * @param object */
public static void put(Context context, String key, Object object)
{
SharedPreferences sp = context.getSharedPreferences(FILE_NAME,
Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sp.edit();
if (object instanceof String)
{
editor.putString(key, (String) object);
} else if (object instanceof Integer)
{
editor.putInt(key, (Integer) object);
} else if (object instanceof Boolean)
{
editor.putBoolean(key, (Boolean) object);
} else if (object instanceof Float)
{
editor.putFloat(key, (Float) object);
} else if (object instanceof Long)
{
editor.putLong(key, (Long) object);
} else
{
editor.putString(key, object.toString());
}
SharedPreferencesCompat.apply(editor);
}
/** * 得到保存数据的方法，我们根据默认值得到保存的数据的具体类型，然后调用相对于的方法获取值 * * @param context * @param key * @param defaultObject * @return */
public static Object get(Context context, String key, Object defaultObject)
{
SharedPreferences sp = context.getSharedPreferences(FILE_NAME,
Context.MODE_PRIVATE);
if (defaultObject instanceof String)
{
return sp.getString(key, (String) defaultObject);
} else if (defaultObject instanceof Integer)
{
return sp.getInt(key, (Integer) defaultObject);
} else if (defaultObject instanceof Boolean)
{
return sp.getBoolean(key, (Boolean) defaultObject);
} else if (defaultObject instanceof Float)
{
return sp.getFloat(key, (Float) defaultObject);
} else if (defaultObject instanceof Long)
{
return sp.getLong(key, (Long) defaultObject);
}
return null;
}
/** * 移除某个key值已经对应的值 * @param context * @param key */
public static void remove(Context context, String key)
{
SharedPreferences sp = context.getSharedPreferences(FILE_NAME,
Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sp.edit();
editor.remove(key);
SharedPreferencesCompat.apply(editor);
}
/** * 清除所有数据 * @param context */
public static void clear(Context context)
{
SharedPreferences sp = context.getSharedPreferences(FILE_NAME,
Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sp.edit();
editor.clear();
SharedPreferencesCompat.apply(editor);
}
/** * 查询某个key是否已经存在 * @param context * @param key * @return */
public static boolean contains(Context context, String key)
{
SharedPreferences sp = context.getSharedPreferences(FILE_NAME,
Context.MODE_PRIVATE);
return sp.contains(key);
}
/** * 返回所有的键值对 * * @param context * @return */
public static Map<String, ?> getAll(Context context)
{
SharedPreferences sp = context.getSharedPreferences(FILE_NAME,
Context.MODE_PRIVATE);
return sp.getAll();
}
/** * 创建一个解决SharedPreferencesCompat.apply方法的一个兼容类 * * @author zhy * */
private static class SharedPreferencesCompat {
private static final Method sApplyMethod = findApplyMethod();
/** * 反射查找apply的方法 * * @return */
@SuppressWarnings({ "unchecked", "rawtypes" })
private static Method findApplyMethod()
{
try
{
Class clz = SharedPreferences.Editor.class;
return clz.getMethod("apply");
} catch (NoSuchMethodException e)
{
}
return null;
}
/** * 如果找到则使用apply执行，否则使用commit * * @param editor */
public static void apply(SharedPreferences.Editor editor)
{
try
{
if (sApplyMethod != null)
{
sApplyMethod.invoke(editor);
return;
}
} catch (IllegalArgumentException e)
{
} catch (IllegalAccessException e)
{
} catch (InvocationTargetException e)
{
}
editor.commit();
}
}
} 对SharedPreference的使用做了建议的封装，对外公布出put，get，remove，clear等等方法；
- 注意一点，里面所有的commit操作使用了SharedPreferencesCompat.apply进行了替代，目的是尽可能的使用apply代替commit.
- 首先说下为什么，因为commit方法是同步的，并且我们很多时候的commit操作都是UI线程中，毕竟是IO操作，尽可能异步；
- 所以我们使用apply进行替代，apply异步的进行写入；
- 但是apply相当于commit来说是new API呢，为了更好的兼容，我们做了适配；
- SharedPreferencesCompat也可以给大家创建兼容类提供了一定的参考~~
2. SPUtils.java
public class PreferencesUtils {
public static String PREFERENCE_NAME = "TrineaAndroidCommon";
private PreferencesUtils() {
throw new AssertionError();
}
/** * put string preferences * * @param context * @param key The name of the preference to modify * @param value The new value for the preference * @return True if the new values were successfully written to persistent storage. */
public static boolean putString(Context context, String key, String value) {
SharedPreferences settings = context.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
SharedPreferences.Editor editor = settings.edit();
editor.putString(key, value);
return editor.commit();
}
/** * get string preferences * * @param context * @param key The name of the preference to retrieve * @return The preference value if it exists, or null. Throws ClassCastException if there is a preference with this * name that is not a string * @see #getString(Context, String, String) */
public static String getString(Context context, String key) {
return getString(context, key, null);
}
/** * get string preferences * * @param context * @param key The name of the preference to retrieve * @param defaultValue Value to return if this preference does not exist * @return The preference value if it exists, or defValue. Throws ClassCastException if there is a preference with * this name that is not a string */
public static String getString(Context context, String key, String defaultValue) {
SharedPreferences settings = context.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
return settings.getString(key, defaultValue);
}
/** * put int preferences * * @param context * @param key The name of the preference to modify * @param value The new value for the preference * @return True if the new values were successfully written to persistent storage. */
public static boolean putInt(Context context, String key, int value) {
SharedPreferences settings = context.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
SharedPreferences.Editor editor = settings.edit();
editor.putInt(key, value);
return editor.commit();
}
/** * get int preferences * * @param context * @param key The name of the preference to retrieve * @return The preference value if it exists, or -1. Throws ClassCastException if there is a preference with this * name that is not a int * @see #getInt(Context, String, int) */
public static int getInt(Context context, String key) {
return getInt(context, key, -1);
}
/** * get int preferences * * @param context * @param key The name of the preference to retrieve * @param defaultValue Value to return if this preference does not exist * @return The preference value if it exists, or defValue. Throws ClassCastException if there is a preference with * this name that is not a int */
public static int getInt(Context context, String key, int defaultValue) {
SharedPreferences settings = context.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
return settings.getInt(key, defaultValue);
}
/** * put long preferences * * @param context * @param key The name of the preference to modify * @param value The new value for the preference * @return True if the new values were successfully written to persistent storage. */
public static boolean putLong(Context context, String key, long value) {
SharedPreferences settings = context.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
SharedPreferences.Editor editor = settings.edit();
editor.putLong(key, value);
return editor.commit();
}
/** * get long preferences * * @param context * @param key The name of the preference to retrieve * @return The preference value if it exists, or -1. Throws ClassCastException if there is a preference with this * name that is not a long * @see #getLong(Context, String, long) */
public static long getLong(Context context, String key) {
return getLong(context, key, -1);
}
/** * get long preferences * * @param context * @param key The name of the preference to retrieve * @param defaultValue Value to return if this preference does not exist * @return The preference value if it exists, or defValue. Throws ClassCastException if there is a preference with * this name that is not a long */
public static long getLong(Context context, String key, long defaultValue) {
SharedPreferences settings = context.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
return settings.getLong(key, defaultValue);
}
/** * put float preferences * * @param context * @param key The name of the preference to modify * @param value The new value for the preference * @return True if the new values were successfully written to persistent storage. */
public static boolean putFloat(Context context, String key, float value) {
SharedPreferences settings = context.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
SharedPreferences.Editor editor = settings.edit();
editor.putFloat(key, value);
return editor.commit();
}
/** * get float preferences * * @param context * @param key The name of the preference to retrieve * @return The preference value if it exists, or -1. Throws ClassCastException if there is a preference with this * name that is not a float * @see #getFloat(Context, String, float) */
public static float getFloat(Context context, String key) {
return getFloat(context, key, -1);
}
/** * get float preferences * * @param context * @param key The name of the preference to retrieve * @param defaultValue Value to return if this preference does not exist * @return The preference value if it exists, or defValue. Throws ClassCastException if there is a preference with * this name that is not a float */
public static float getFloat(Context context, String key, float defaultValue) {
SharedPreferences settings = context.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
return settings.getFloat(key, defaultValue);
}
/** * put boolean preferences * * @param context * @param key The name of the preference to modify * @param value The new value for the preference * @return True if the new values were successfully written to persistent storage. */
public static boolean putBoolean(Context context, String key, boolean value) {
SharedPreferences settings = context.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
SharedPreferences.Editor editor = settings.edit();
editor.putBoolean(key, value);
return editor.commit();
}
/** * get boolean preferences, default is false * * @param context * @param key The name of the preference to retrieve * @return The preference value if it exists, or false. Throws ClassCastException if there is a preference with this * name that is not a boolean * @see #getBoolean(Context, String, boolean) */
public static boolean getBoolean(Context context, String key) {
return getBoolean(context, key, false);
}
/** * get boolean preferences * * @param context * @param key The name of the preference to retrieve * @param defaultValue Value to return if this preference does not exist * @return The preference value if it exists, or defValue. Throws ClassCastException if there is a preference with * this name that is not a boolean */
public static boolean getBoolean(Context context, String key, boolean defaultValue) {
SharedPreferences settings = context.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
return settings.getBoolean(key, defaultValue);
}
}四、单位转换类 DensityUtils.java
public class DensityUtils {
private DensityUtils()
{
/* cannot be instantiated */
throw new UnsupportedOperationException("cannot be instantiated");
}
/** * dp转px * * @param context * @param val * @return */
public static int dp2px(Context context, float dpVal)
{
return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
dpVal, context.getResources().getDisplayMetrics());
}
/** * sp转px * * @param context * @param val * @return */
public static int sp2px(Context context, float spVal)
{
return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP,
spVal, context.getResources().getDisplayMetrics());
}
/** * px转dp * * @param context * @param pxVal * @return */
public static float px2dp(Context context, float pxVal)
{
final float scale = context.getResources().getDisplayMetrics().density;
return (pxVal / scale);
}
/** * px转sp * * @param fontScale * @param pxVal * @return */
public static float px2sp(Context context, float pxVal)
{
return (pxVal / context.getResources().getDisplayMetrics().scaledDensity);
}
} TypedValue：
Container for a dynamically typed data value. Primarily used with Resources for holding resource values.applyDimension(int unit, float value, DisplayMetrics metrics)：
Converts an unpacked complex data value holding a dimension to its final floating point value.
五、SD卡相关辅助类 SDCardUtils.java
public class SDCardUtils {
private SDCardUtils()
{
/* cannot be instantiated */
throw new UnsupportedOperationException("cannot be instantiated");
}
/** * 判断SDCard是否可用 * * @return */
public static boolean isSDCardEnable()
{
return Environment.getExternalStorageState().equals(
Environment.MEDIA_MOUNTED);
}
/** * 获取SD卡路径 * * @return */
public static String getSDCardPath()
{
return Environment.getExternalStorageDirectory().getAbsolutePath()
+ File.separator;
}
/** * 获取SD卡的剩余容量 单位byte * * @return */
public static long getSDCardAllSize()
{
if (isSDCardEnable())
{
StatFs stat = new StatFs(getSDCardPath());
// 获取空闲的数据块的数量
long availableBlocks = (long) stat.getAvailableBlocks() - 4;
// 获取单个数据块的大小（byte）
long freeBlocks = stat.getAvailableBlocks();
return freeBlocks * availableBlocks;
}
return 0;
}
/** * 获取指定路径所在空间的剩余可用容量字节数，单位byte * * @param filePath * @return 容量字节 SDCard可用空间，内部存储可用空间 */
public static long getFreeBytes(String filePath)
{
// 如果是sd卡的下的路径，则获取sd卡可用容量
if (filePath.startsWith(getSDCardPath()))
{
filePath = getSDCardPath();
} else
{// 如果是内部存储的路径，则获取内存存储的可用容量
filePath = Environment.getDataDirectory().getAbsolutePath();
}
StatFs stat = new StatFs(filePath);
long availableBlocks = (long) stat.getAvailableBlocks() - 4;
return stat.getBlockSize() * availableBlocks;
}
/** * 获取系统存储路径 * * @return */
public static String getRootDirectoryPath()
{
return Environment.getRootDirectory().getAbsolutePath();
}
} StatFs是Android提供的一个类：
Retrieve overall information about the space on a filesystem. This is a wrapper for Unix statvfs().
检索一个文件系统的整体信息空间。这是一个Unix statvfs() 包装器。
六、屏幕相关辅助类 ScreenUtils.java
public class ScreenUtils {
private ScreenUtils()
{
/* cannot be instantiated */
throw new UnsupportedOperationException("cannot be instantiated");
}
/** * 获得屏幕高度 * * @param context * @return */
public static int getScreenWidth(Context context)
{
WindowManager wm = (WindowManager) context
.getSystemService(Context.WINDOW_SERVICE);
DisplayMetrics outMetrics = new DisplayMetrics();
wm.getDefaultDisplay().getMetrics(outMetrics);
return outMetrics.widthPixels;
}
/** * 获得屏幕宽度 * * @param context * @return */
public static int getScreenHeight(Context context)
{
WindowManager wm = (WindowManager) context
.getSystemService(Context.WINDOW_SERVICE);
DisplayMetrics outMetrics = new DisplayMetrics();
wm.getDefaultDisplay().getMetrics(outMetrics);
return outMetrics.heightPixels;
}
/** * 获得状态栏的高度 * * @param context * @return */
public static int getStatusHeight(Context context)
{
int statusHeight = -1;
try
{
Class<?> clazz = Class.forName("com.android.internal.R$dimen");
Object object = clazz.newInstance();
int height = Integer.parseInt(clazz.getField("status_bar_height")
.get(object).toString());
statusHeight = context.getResources().getDimensionPixelSize(height);
} catch (Exception e)
{
e.printStackTrace();
}
return statusHeight;
}
/** * 获取当前屏幕截图，包含状态栏 * * @param activity * @return */
public static Bitmap snapShotWithStatusBar(Activity activity)
{
View view = activity.getWindow().getDecorView();
view.setDrawingCacheEnabled(true);
view.buildDrawingCache();
Bitmap bmp = view.getDrawingCache();
int width = getScreenWidth(activity);
int height = getScreenHeight(activity);
Bitmap bp = null;
bp = Bitmap.createBitmap(bmp, 0, 0, width, height);
view.destroyDrawingCache();
return bp;
}
/** * 获取当前屏幕截图，不包含状态栏 * * @param activity * @return */
public static Bitmap snapShotWithoutStatusBar(Activity activity)
{
View view = activity.getWindow().getDecorView();
view.setDrawingCacheEnabled(true);
view.buildDrawingCache();
Bitmap bmp = view.getDrawingCache();
Rect frame = new Rect();
activity.getWindow().getDecorView().getWindowVisibleDisplayFrame(frame);
int statusBarHeight = frame.top;
int width = getScreenWidth(activity);
int height = getScreenHeight(activity);
Bitmap bp = null;
bp = Bitmap.createBitmap(bmp, 0, statusBarHeight, width, height
- statusBarHeight);
view.destroyDrawingCache();
return bp;
}
} 七、App相关辅助类 APPUtils.java
public class AppUtils {
private AppUtils()
{
/* cannot be instantiated */
throw new UnsupportedOperationException("cannot be instantiated");
}
/** * 获取应用程序名称 */
public static String getAppName(Context context)
{
try
{
PackageManager packageManager = context.getPackageManager();
PackageInfo packageInfo = packageManager.getPackageInfo(
context.getPackageName(), 0);
int labelRes = packageInfo.applicationInfo.labelRes;
return context.getResources().getString(labelRes);
} catch (NameNotFoundException e)
{
e.printStackTrace();
}
return null;
}
/** * [获取应用程序版本名称信息] * * @param context * @return 当前应用的版本名称 */
public static String getVersionName(Context context)
{
try
{
PackageManager packageManager = context.getPackageManager();
PackageInfo packageInfo = packageManager.getPackageInfo(
context.getPackageName(), 0);
return packageInfo.versionName;
} catch (NameNotFoundException e)
{
e.printStackTrace();
}
return null;
}
} 八、软键盘相关辅助类KeyBoardUtils.java
/** * 打开或关闭软键盘 */
public class KeyBoardUtils {
/** * 打卡软键盘 * * @param mEditText 输入框 * @param mContext 上下文 */
public static void openKeybord(EditText mEditText, Context mContext)
{
InputMethodManager imm = (InputMethodManager) mContext
.getSystemService(Context.INPUT_METHOD_SERVICE);
imm.showSoftInput(mEditText, InputMethodManager.RESULT_SHOWN);
imm.toggleSoftInput(InputMethodManager.SHOW_FORCED,
InputMethodManager.HIDE_IMPLICIT_ONLY);
}
/** * 关闭软键盘 * * @param mEditText 输入框 * @param mContext 上下文 */
public static void closeKeybord(EditText mEditText, Context mContext)
{
InputMethodManager imm = (InputMethodManager) mContext
.getSystemService(Context.INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(mEditText.getWindowToken(), 0);
}
} 九、网络相关辅助类 NetUtils.java
public class NetUtils {
private NetUtils()
{
/* cannot be instantiated */
throw new UnsupportedOperationException("cannot be instantiated");
}
/** * 判断网络是否连接 */
public static boolean isConnected(Context context)
{
ConnectivityManager connectivity = (ConnectivityManager) context
.getSystemService(Context.CONNECTIVITY_SERVICE);
if (null != connectivity)
{
NetworkInfo info = connectivity.getActiveNetworkInfo();
if (null != info && info.isConnected())
{
if (info.getState() == NetworkInfo.State.CONNECTED)
{
return true;
}
}
}
return false;
}
/** * 判断是否是wifi连接 */
public static boolean isWifi(Context context)
{
ConnectivityManager cm = (ConnectivityManager) context
.getSystemService(Context.CONNECTIVITY_SERVICE);
if (cm == null)
return false;
return cm.getActiveNetworkInfo().getType() == ConnectivityManager.TYPE_WIFI;
}
/** * 打开网络设置界面 */
public static void openSetting(Activity activity)
{
Intent intent = new Intent("/");
ComponentName cm = new ComponentName("com.android.settings",
"com.android.settings.WirelessSettings");
intent.setComponent(cm);
intent.setAction("android.intent.action.VIEW");
activity.startActivityForResult(intent, 0);
}
} 十、Http相关辅助类 HttpUtils.java
/** * Http请求的工具类 */
public class HttpUtils {
private static final int TIMEOUT_IN_MILLIONS = 5000;
public interface CallBack {
void onRequestComplete(String result);
}
/** * 异步的Get请求 * * @param urlStr * @param callBack */
public static void doGetAsyn(final String urlStr, final CallBack callBack)
{
new Thread()
{
public void run()
{
try
{
String result = doGet(urlStr);
if (callBack != null)
{
callBack.onRequestComplete(result);
}
} catch (Exception e)
{
e.printStackTrace();
}
};
}.start();
}
/** * 异步的Post请求 * @param urlStr * @param params * @param callBack * @throws Exception */
public static void doPostAsyn(final String urlStr, final String params,
final CallBack callBack) throws Exception
{
new Thread()
{
public void run()
{
try
{
String result = doPost(urlStr, params);
if (callBack != null)
{
callBack.onRequestComplete(result);
}
} catch (Exception e)
{
e.printStackTrace();
}
};
}.start();
}
/** * Get请求，获得返回数据 * * @param urlStr * @return * @throws Exception */
public static String doGet(String urlStr)
{
URL url = null;
HttpURLConnection conn = null;
InputStream is = null;
ByteArrayOutputStream baos = null;
try
{
url = new URL(urlStr);
conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(TIMEOUT_IN_MILLIONS);
conn.setConnectTimeout(TIMEOUT_IN_MILLIONS);
conn.setRequestMethod("GET");
conn.setRequestProperty("accept", "*/*");
conn.setRequestProperty("connection", "Keep-Alive");
if (conn.getResponseCode() == 200)
{
is = conn.getInputStream();
baos = new ByteArrayOutputStream();
int len = -1;
byte[] buf = new byte[128];
while ((len = is.read(buf)) != -1)
{
baos.write(buf, 0, len);
}
baos.flush();
return baos.toString();
} else
{
throw new RuntimeException(" responseCode is not 200 ... ");
}
} catch (Exception e)
{
e.printStackTrace();
} finally
{
try
{
if (is != null)
is.close();
} catch (IOException e)
{
}
try
{
if (baos != null)
baos.close();
} catch (IOException e)
{
}
conn.disconnect();
}
return null ;
}
/** * 向指定 URL 发送POST方法的请求 * * @param url * 发送请求的 URL * @param param * 请求参数，请求参数应该是 name1=value1&name2=value2 的形式。 * @return 所代表远程资源的响应结果 * @throws Exception */
public static String doPost(String url, String param)
{
PrintWriter out = null;
BufferedReader in = null;
String result = "";
try
{
URL realUrl = new URL(url);
// 打开和URL之间的连接
HttpURLConnection conn = (HttpURLConnection) realUrl
.openConnection();
// 设置通用的请求属性
conn.setRequestProperty("accept", "*/*");
conn.setRequestProperty("connection", "Keep-Alive");
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Type",
"application/x-www-form-urlencoded");
conn.setRequestProperty("charset", "utf-8");
conn.setUseCaches(false);
// 发送POST请求必须设置如下两行
conn.setDoOutput(true);
conn.setDoInput(true);
conn.setReadTimeout(TIMEOUT_IN_MILLIONS);
conn.setConnectTimeout(TIMEOUT_IN_MILLIONS);
if (param != null && !param.trim().equals(""))
{
// 获取URLConnection对象对应的输出流
out = new PrintWriter(conn.getOutputStream());
// 发送请求参数
out.print(param);
// flush输出流的缓冲
out.flush();
}
// 定义BufferedReader输入流来读取URL的响应
in = new BufferedReader(
new InputStreamReader(conn.getInputStream()));
String line;
while ((line = in.readLine()) != null)
{
result += line;
}
} catch (Exception e)
{
e.printStackTrace();
}
// 使用finally块来关闭输出流、输入流
finally
{
try
{
if (out != null)
{
out.close();
}
if (in != null)
{
in.close();
}
} catch (IOException ex)
{
ex.printStackTrace();
}
}
return result;
}
} 十一、时间工具类 TimeUtils.java
public class TimeUtils {
public static final SimpleDateFormat DEFAULT_DATE_FORMAT =
new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
public static final SimpleDateFormat DATE_FORMAT_DATE =
new SimpleDateFormat("yyyy-MM-dd");
private TimeUtils() {
throw new AssertionError();
}
/** * long time to string * * @param timeInMillis * @param dateFormat * @return */
public static String getTime(long timeInMillis, SimpleDateFormat dateFormat) {
return dateFormat.format(new Date(timeInMillis));
}
/** * long time to string, format is {@link #DEFAULT_DATE_FORMAT} * * @param timeInMillis * @return */
public static String getTime(long timeInMillis) {
return getTime(timeInMillis, DEFAULT_DATE_FORMAT);
}
/** * get current time in milliseconds * * @return */
public static long getCurrentTimeInLong() {
return System.currentTimeMillis();
}
/** * get current time in milliseconds, format is {@link #DEFAULT_DATE_FORMAT} * * @return */
public static String getCurrentTimeInString() {
return getTime(getCurrentTimeInLong());
}
/** * get current time in milliseconds * * @return */
public static String getCurrentTimeInString(SimpleDateFormat dateFormat) {
return getTime(getCurrentTimeInLong(), dateFormat);
}
}十二、文件工具类 FileUtils.java
public class FileUtils {
public final static String FILE_EXTENSION_SEPARATOR = ".";
private FileUtils() {
throw new AssertionError();
}
/** * read file * * @param filePath * @param charsetName The name of a supported {@link java.nio.charset.Charset </code>charset<code>} * @return if file not exist, return null, else return content of file * @throws RuntimeException if an error occurs while operator BufferedReader */
public static StringBuilder readFile(String filePath, String charsetName) {
File file = new File(filePath);
StringBuilder fileContent = new StringBuilder("");
if (file == null || !file.isFile()) {
return null;
}
BufferedReader reader = null;
try {
InputStreamReader is = new InputStreamReader(new FileInputStream(file), charsetName);
reader = new BufferedReader(is);
String line = null;
while ((line = reader.readLine()) != null) {
if (!fileContent.toString().equals("")) {
fileContent.append("\r\n");
}
fileContent.append(line);
}
return fileContent;
} catch (IOException e) {
throw new RuntimeException("IOException occurred. ", e);
} finally {
IOUtils.close(reader);
}
}
/** * write file * * @param filePath * @param content * @param append is append, if true, write to the end of file, else clear content of file and write into it * @return return false if content is empty, true otherwise * @throws RuntimeException if an error occurs while operator FileWriter */
public static boolean writeFile(String filePath, String content, boolean append) {
if (StringUtils.isEmpty(content)) {
return false;
}
FileWriter fileWriter = null;
try {
makeDirs(filePath);
fileWriter = new FileWriter(filePath, append);
fileWriter.write(content);
return true;
} catch (IOException e) {
throw new RuntimeException("IOException occurred. ", e);
} finally {
IOUtils.close(fileWriter);
}
}
/** * write file * * @param filePath * @param contentList * @param append is append, if true, write to the end of file, else clear content of file and write into it * @return return false if contentList is empty, true otherwise * @throws RuntimeException if an error occurs while operator FileWriter */
public static boolean writeFile(String filePath, List<String> contentList, boolean append) {
if (ListUtils.isEmpty(contentList)) {
return false;
}
FileWriter fileWriter = null;
try {
makeDirs(filePath);
fileWriter = new FileWriter(filePath, append);
int i = 0;
for (String line : contentList) {
if (i++ > 0) {
fileWriter.write("\r\n");
}
fileWriter.write(line);
}
return true;
} catch (IOException e) {
throw new RuntimeException("IOException occurred. ", e);
} finally {
IOUtils.close(fileWriter);
}
}
/** * write file, the string will be written to the begin of the file * * @param filePath * @param content * @return */
public static boolean writeFile(String filePath, String content) {
return writeFile(filePath, content, false);
}
/** * write file, the string list will be written to the begin of the file * * @param filePath * @param contentList * @return */
public static boolean writeFile(String filePath, List<String> contentList) {
return writeFile(filePath, contentList, false);
}
/** * write file, the bytes will be written to the begin of the file * * @param filePath * @param stream * @return * @see {@link #writeFile(String, InputStream, boolean)} */
public static boolean writeFile(String filePath, InputStream stream) {
return writeFile(filePath, stream, false);
}
/** * write file * * @param file the file to be opened for writing. * @param stream the input stream * @param append if <code>true</code>, then bytes will be written to the end of the file rather than the beginning * @return return true * @throws RuntimeException if an error occurs while operator FileOutputStream */
public static boolean writeFile(String filePath, InputStream stream, boolean append) {
return writeFile(filePath != null ? new File(filePath) : null, stream, append);
}
/** * write file, the bytes will be written to the begin of the file * * @param file * @param stream * @return * @see {@link #writeFile(File, InputStream, boolean)} */
public static boolean writeFile(File file, InputStream stream) {
return writeFile(file, stream, false);
}
/** * write file * * @param file the file to be opened for writing. * @param stream the input stream * @param append if <code>true</code>, then bytes will be written to the end of the file rather than the beginning * @return return true * @throws RuntimeException if an error occurs while operator FileOutputStream */
public static boolean writeFile(File file, InputStream stream, boolean append) {
OutputStream o = null;
try {
makeDirs(file.getAbsolutePath());
o = new FileOutputStream(file, append);
byte data[] = new byte[1024];
int length = -1;
while ((length = stream.read(data)) != -1) {
o.write(data, 0, length);
}
o.flush();
return true;
} catch (FileNotFoundException e) {
throw new RuntimeException("FileNotFoundException occurred. ", e);
} catch (IOException e) {
throw new RuntimeException("IOException occurred. ", e);
} finally {
IOUtils.close(o);
IOUtils.close(stream);
}
}
/** * move file * * @param sourceFilePath * @param destFilePath */
public static void moveFile(String sourceFilePath, String destFilePath) {
if (TextUtils.isEmpty(sourceFilePath) || TextUtils.isEmpty(destFilePath)) {
throw new RuntimeException("Both sourceFilePath and destFilePath cannot be null.");
}
moveFile(new File(sourceFilePath), new File(destFilePath));
}
/** * move file * * @param srcFile * @param destFile */
public static void moveFile(File srcFile, File destFile) {
boolean rename = srcFile.renameTo(destFile);
if (!rename) {
copyFile(srcFile.getAbsolutePath(), destFile.getAbsolutePath());
deleteFile(srcFile.getAbsolutePath());
}
}
/** * copy file * * @param sourceFilePath * @param destFilePath * @return * @throws RuntimeException if an error occurs while operator FileOutputStream */
public static boolean copyFile(String sourceFilePath, String destFilePath) {
InputStream inputStream = null;
try {
inputStream = new FileInputStream(sourceFilePath);
} catch (FileNotFoundException e) {
throw new RuntimeException("FileNotFoundException occurred. ", e);
}
return writeFile(destFilePath, inputStream);
}
/** * read file to string list, a element of list is a line * * @param filePath * @param charsetName The name of a supported {@link java.nio.charset.Charset </code>charset<code>} * @return if file not exist, return null, else return content of file * @throws RuntimeException if an error occurs while operator BufferedReader */
public static List<String> readFileToList(String filePath, String charsetName) {
File file = new File(filePath);
List<String> fileContent = new ArrayList<String>();
if (file == null || !file.isFile()) {
return null;
}
BufferedReader reader = null;
try {
InputStreamReader is = new InputStreamReader(new FileInputStream(file), charsetName);
reader = new BufferedReader(is);
String line = null;
while ((line = reader.readLine()) != null) {
fileContent.add(line);
}
return fileContent;
} catch (IOException e) {
throw new RuntimeException("IOException occurred. ", e);
} finally {
IOUtils.close(reader);
}
}
/** * get file name from path, not include suffix * * <pre> * getFileNameWithoutExtension(null) = null * getFileNameWithoutExtension("") = "" * getFileNameWithoutExtension(" ") = " " * getFileNameWithoutExtension("abc") = "abc" * getFileNameWithoutExtension("a.mp3") = "a" * getFileNameWithoutExtension("a.b.rmvb") = "a.b" * getFileNameWithoutExtension("c:\\") = "" * getFileNameWithoutExtension("c:\\a") = "a" * getFileNameWithoutExtension("c:\\a.b") = "a" * getFileNameWithoutExtension("c:a.txt\\a") = "a" * getFileNameWithoutExtension("/home/admin") = "admin" * getFileNameWithoutExtension("/home/admin/a.txt/b.mp3") = "b" * </pre> * * @param filePath * @return file name from path, not include suffix * @see */
public static String getFileNameWithoutExtension(String filePath) {
if (StringUtils.isEmpty(filePath)) {
return filePath;
}
int extenPosi = filePath.lastIndexOf(FILE_EXTENSION_SEPARATOR);
int filePosi = filePath.lastIndexOf(File.separator);
if (filePosi == -1) {
return (extenPosi == -1 ? filePath : filePath.substring(0, extenPosi));
}
if (extenPosi == -1) {
return filePath.substring(filePosi + 1);
}
return (filePosi < extenPosi ? filePath.substring(filePosi + 1, extenPosi) : filePath.substring(filePosi + 1));
}
/** * get file name from path, include suffix * * <pre> * getFileName(null) = null * getFileName("") = "" * getFileName(" ") = " " * getFileName("a.mp3") = "a.mp3" * getFileName("a.b.rmvb") = "a.b.rmvb" * getFileName("abc") = "abc" * getFileName("c:\\") = "" * getFileName("c:\\a") = "a" * getFileName("c:\\a.b") = "a.b" * getFileName("c:a.txt\\a") = "a" * getFileName("/home/admin") = "admin" * getFileName("/home/admin/a.txt/b.mp3") = "b.mp3" * </pre> * * @param filePath * @return file name from path, include suffix */
public static String getFileName(String filePath) {
if (StringUtils.isEmpty(filePath)) {
return filePath;
}
int filePosi = filePath.lastIndexOf(File.separator);
return (filePosi == -1) ? filePath : filePath.substring(filePosi + 1);
}
/** * get folder name from path * * <pre> * getFolderName(null) = null * getFolderName("") = "" * getFolderName(" ") = "" * getFolderName("a.mp3") = "" * getFolderName("a.b.rmvb") = "" * getFolderName("abc") = "" * getFolderName("c:\\") = "c:" * getFolderName("c:\\a") = "c:" * getFolderName("c:\\a.b") = "c:" * getFolderName("c:a.txt\\a") = "c:a.txt" * getFolderName("c:a\\b\\c\\d.txt") = "c:a\\b\\c" * getFolderName("/home/admin") = "/home" * getFolderName("/home/admin/a.txt/b.mp3") = "/home/admin/a.txt" * </pre> * * @param filePath * @return */
public static String getFolderName(String filePath) {
if (StringUtils.isEmpty(filePath)) {
return filePath;
}
int filePosi = filePath.lastIndexOf(File.separator);
return (filePosi == -1) ? "" : filePath.substring(0, filePosi);
}
/** * get suffix of file from path * * <pre> * getFileExtension(null) = "" * getFileExtension("") = "" * getFileExtension(" ") = " " * getFileExtension("a.mp3") = "mp3" * getFileExtension("a.b.rmvb") = "rmvb" * getFileExtension("abc") = "" * getFileExtension("c:\\") = "" * getFileExtension("c:\\a") = "" * getFileExtension("c:\\a.b") = "b" * getFileExtension("c:a.txt\\a") = "" * getFileExtension("/home/admin") = "" * getFileExtension("/home/admin/a.txt/b") = "" * getFileExtension("/home/admin/a.txt/b.mp3") = "mp3" * </pre> * * @param filePath * @return */
public static String getFileExtension(String filePath) {
if (StringUtils.isBlank(filePath)) {
return filePath;
}
int extenPosi = filePath.lastIndexOf(FILE_EXTENSION_SEPARATOR);
int filePosi = filePath.lastIndexOf(File.separator);
if (extenPosi == -1) {
return "";
}
return (filePosi >= extenPosi) ? "" : filePath.substring(extenPosi + 1);
}
/** * Creates the directory named by the trailing filename of this file, including the complete directory path required * to create this directory. <br/> * <br/> * <ul> * <strong>Attentions:</strong> * <li>makeDirs("C:\\Users\\Trinea") can only create users folder</li> * <li>makeFolder("C:\\Users\\Trinea\\") can create Trinea folder</li> * </ul> * * @param filePath * @return true if the necessary directories have been created or the target directory already exists, false one of * the directories can not be created. * <ul> * <li>if {@link FileUtils#getFolderName(String)} return null, return false</li> * <li>if target directory already exists, return true</li> * <li>return {@link java.io.File#makeFolder}</li> * </ul> */
public static boolean makeDirs(String filePath) {
String folderName = getFolderName(filePath);
if (StringUtils.isEmpty(folderName)) {
return false;
}
File folder = new File(folderName);
return (folder.exists() && folder.isDirectory()) ? true : folder.mkdirs();
}
/** * @param filePath * @return * @see #makeDirs(String) */
public static boolean makeFolders(String filePath) {
return makeDirs(filePath);
}
/** * Indicates if this file represents a file on the underlying file system. * * @param filePath * @return */
public static boolean isFileExist(String filePath) {
if (StringUtils.isBlank(filePath)) {
return false;
}
File file = new File(filePath);
return (file.exists() && file.isFile());
}
/** * Indicates if this file represents a directory on the underlying file system. * * @param directoryPath * @return */
public static boolean isFolderExist(String directoryPath) {
if (StringUtils.isBlank(directoryPath)) {
return false;
}
File dire = new File(directoryPath);
return (dire.exists() && dire.isDirectory());
}
/** * delete file or directory * <ul> * <li>if path is null or empty, return true</li> * <li>if path not exist, return true</li> * <li>if path exist, delete recursion. return true</li> * <ul> * * @param path * @return */
public static boolean deleteFile(String path) {
if (StringUtils.isBlank(path)) {
return true;
}
File file = new File(path);
if (!file.exists()) {
return true;
}
if (file.isFile()) {
return file.delete();
}
if (!file.isDirectory()) {
return false;
}
for (File f : file.listFiles()) {
if (f.isFile()) {
f.delete();
} else if (f.isDirectory()) {
deleteFile(f.getAbsolutePath());
}
}
return file.delete();
}
/** * get file size * <ul> * <li>if path is null or empty, return -1</li> * <li>if path exist and it is a file, return file size, else return -1</li> * <ul> * * @param path * @return returns the length of this file in bytes. returns -1 if the file does not exist. */
public static long getFileSize(String path) {
if (StringUtils.isBlank(path)) {
return -1;
}
File file = new File(path);
return (file.exists() && file.isFile() ? file.length() : -1);
}
}十三、assets和raw资源工具类 ResourceUtils.java
public class ResourceUtils {
private ResourceUtils() {
throw new AssertionError();
}
/** * get an asset using ACCESS_STREAMING mode. This provides access to files that have been bundled with an * application as assets -- that is, files placed in to the "assets" directory. * * @param context * @param fileName The name of the asset to open. This name can be hierarchical. * @return */
public static String geFileFromAssets(Context context, String fileName) {
if (context == null || StringUtils.isEmpty(fileName)) {
return null;
}
StringBuilder s = new StringBuilder("");
try {
InputStreamReader in = new InputStreamReader(context.getResources().getAssets().open(fileName));
BufferedReader br = new BufferedReader(in);
String line;
while ((line = br.readLine()) != null) {
s.append(line);
}
return s.toString();
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
/** * get content from a raw resource. This can only be used with resources whose value is the name of an asset files * -- that is, it can be used to open drawable, sound, and raw resources; it will fail on string and color * resources. * * @param context * @param resId The resource identifier to open, as generated by the appt tool. * @return */
public static String geFileFromRaw(Context context, int resId) {
if (context == null) {
return null;
}
StringBuilder s = new StringBuilder();
try {
InputStreamReader in = new InputStreamReader(context.getResources().openRawResource(resId));
BufferedReader br = new BufferedReader(in);
String line;
while ((line = br.readLine()) != null) {
s.append(line);
}
return s.toString();
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
/** * same to {@link ResourceUtils#geFileFromAssets(Context, String)}, but return type is List<String> * * @param context * @param fileName * @return */
public static List<String> geFileToListFromAssets(Context context, String fileName) {
if (context == null || StringUtils.isEmpty(fileName)) {
return null;
}
List<String> fileContent = new ArrayList<String>();
try {
InputStreamReader in = new InputStreamReader(context.getResources().getAssets().open(fileName));
BufferedReader br = new BufferedReader(in);
String line;
while ((line = br.readLine()) != null) {
fileContent.add(line);
}
br.close();
return fileContent;
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
/** * same to {@link ResourceUtils#geFileFromRaw(Context, int)}, but return type is List<String> * * @param context * @param resId * @return */
public static List<String> geFileToListFromRaw(Context context, int resId) {
if (context == null) {
return null;
}
List<String> fileContent = new ArrayList<String>();
BufferedReader reader = null;
try {
InputStreamReader in = new InputStreamReader(context.getResources().openRawResource(resId));
reader = new BufferedReader(in);
String line = null;
while ((line = reader.readLine()) != null) {
fileContent.add(line);
}
reader.close();
return fileContent;
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
}十四、单例工具类 SingletonUtils.java
public abstract class SingletonUtils<T> {
private T instance;
protected abstract T newInstance();
public final T getInstance() {
if (instance == null) {
synchronized (SingletonUtils.class) {
if (instance == null) {
instance = newInstance();
}
}
}
return instance;
}
}十五、数据库工具类 SqliteUtils.java
public class SqliteUtils {
private static volatile SqliteUtils instance;
private DbHelper dbHelper;
private SQLiteDatabase db;
private SqliteUtils(Context context) {
dbHelper = new DbHelper(context);
db = dbHelper.getWritableDatabase();
}
public static SqliteUtils getInstance(Context context) {
if (instance == null) {
synchronized (SqliteUtils.class) {
if (instance == null) {
instance = new SqliteUtils(context);
}
}
}
return instance;
}
public SQLiteDatabase getDb() {
return db;
}
}更多工具类的设计可参考 GitHub项目：Trinea/android-common
十六、
参考文章：
- Android快速开发系列 10个常用工具类
- GitHub项目：Trinea/android-common