工具类:HttpURLConnHelper(实现网络访问文件,将获取到数据储存在文件流中)

package org.moblie.train.zday09_json_MyUtils;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.Map;

public class HttpURLConnHelper {
    /** * 作用:实现网络访问文件,将获取到数据储存在文件流中 * * @param url * :访问网络的url地址 * @return inputstream */
    public static InputStream loadFileFromURL(String urlString) {
        BufferedInputStream bis = null;
        HttpURLConnection httpConn = null;
        try {
            // 创建url对象
            URL urlObj = new URL(urlString);
            // 创建HttpURLConnection对象,通过这个对象打开跟远程服务器之间的连接
            httpConn = (HttpURLConnection) urlObj.openConnection();

            httpConn.setDoInput(true);
            httpConn.setRequestMethod("GET");
            httpConn.setConnectTimeout(5000);
            httpConn.connect();

            // 判断跟服务器的连接状态。如果是200,则说明连接正常,服务器有响应
            if (httpConn.getResponseCode() == 200) {
                // 服务器有响应后,会将访问的url页面中的内容放进inputStream中,使用httpConn就可以获取到这个字节流
                bis = new BufferedInputStream(httpConn.getInputStream());
                return bis;
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                // 对流对象进行关闭,对Http连接对象进行关闭。以便释放资源。
                bis.close();
                httpConn.disconnect();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return null;
    }

    /** * 作用:实现网络访问文件,将获取到的数据存在字节数组中 * * @param url * :访问网络的url地址 * @return byte[] */
    public static byte[] loadByteFromURL(String url) {
        HttpURLConnection httpConn = null;
        BufferedInputStream bis = null;
        try {
            URL urlObj = new URL(url);
            httpConn = (HttpURLConnection) urlObj.openConnection();
            httpConn.setRequestMethod("GET");
            httpConn.setDoInput(true);
            httpConn.setConnectTimeout(5000);
            httpConn.connect();

            if (httpConn.getResponseCode() == 200) {
                bis = new BufferedInputStream(httpConn.getInputStream());
                return streamToByte(bis);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (bis != null) {
                    bis.close();
                }
                httpConn.disconnect();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return null;
    }

    /** * 作用:实现网络访问文件,将获取到的数据保存在指定目录中 * * @param url * :访问网络的url地址 * @return byte[] */
    public static boolean saveFileFromURL(String url, File destFile) {
        HttpURLConnection httpConn = null;
        BufferedInputStream bis = null;
        BufferedOutputStream bos = null;
        try {
            bos = new BufferedOutputStream(new FileOutputStream(destFile));
            URL urlObj = new URL(url);
            httpConn = (HttpURLConnection) urlObj.openConnection();
            httpConn.setRequestMethod("GET");
            httpConn.setDoInput(true);
            httpConn.setConnectTimeout(5000);
            httpConn.connect();

            if (httpConn.getResponseCode() == 200) {
                bis = new BufferedInputStream(httpConn.getInputStream());
                int c = 0;
                byte[] buffer = new byte[8 * 1024];
                while ((c = bis.read(buffer)) != -1) {
                    bos.write(buffer, 0, c);
                    bos.flush();
                }
            }
            return true;
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (bis != null) {
                    bis.close();
                }
                if (bos != null) {
                    bos.close();
                }
                httpConn.disconnect();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return false;
    }

    /** * 作用:实现网络访问文件,先给服务器通过“POST”方式提交数据,再返回相应的数据 * * @param url * :访问网络的url地址 * @param params * :访问url时,需要传递给服务器的参数。格式为:username=wangxiangjun&password=abcde& * qq=32432432 * 为了防止传中文参数时出现编码问题。采用URLEncoder.encode()对含中文的字符串进行编码处理。 * 服务器端会自动对进行过编码的字符串进行decode()解码。 * @return byte[] */
    public static byte[] doPostSubmit(String url, String params) {
        BufferedOutputStream bos = null;
        BufferedInputStream bis = null;
        HttpURLConnection httpConn = null;
        try {
            URL urlObj = new URL(url);
            httpConn = (HttpURLConnection) urlObj.openConnection();

            // 如果通过post方式给服务器传递数据,那么setDoOutput()必须设置为true。否则会异常。
            // 默认情况下setDoOutput()为false。
            // 其实也应该设置setDoInput(),但是因为setDoInput()默认为true。所以不一定要写。

            httpConn.setDoInput(true);
            httpConn.setDoOutput(true);
            httpConn.setRequestMethod("POST");
            httpConn.setConnectTimeout(5 * 1000);
            // 设置请求方式。请求方式有两种:POST/GET。注意要全大写。
            // POST传递数据量大,数据更安全,地址栏中不会显示传输数据。
            // 而GET会将传输的数据暴露在地址栏中,传输的数据量大小有限制,相对POST不够安全。但是GET操作灵活简便。

            // 判断是否要往服务器传递参数。如果不传递参数,那么就没有必要使用输出流了。
            if (params != null) {
                byte[] data = params.getBytes();
                bos = new BufferedOutputStream(httpConn.getOutputStream());
                bos.write(data);
                bos.flush();
            }
            // 判断访问网络的连接状态
            if (httpConn.getResponseCode() == 200) {
                bis = new BufferedInputStream(httpConn.getInputStream());
                // 将获取到的输入流转成字节数组
                return streamToByte(bis);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (bis != null) {
                    bis.close();
                }
                if (bos != null) {
                    bos.close();
                }
                httpConn.disconnect();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return null;
    }

    /** * 网络访问,上传附件 五个参数: 1、String url:指定表单提交的url地址 2、Map<String, String> * map:将上传控件之外的其他控件的数据信息存入map对象 3、String filePath:指定要上传到服务器的文件的客户端路径 * 4、byte[] body_data:获取到要上传的文件的输入流信息,通过ByteArrayOutputStream流转成byte[] * 5、String charset:设置字符集 */
    public static String doPostSubmitBody(String url, Map<String, String> map,
            String filePath, byte[] body_data, String charset) {
        // 设置三个常用字符串常量:换行、前缀、分界线(NEWLINE、PREFIX、BOUNDARY);
        final String NEWLINE = "\r\n";
        final String PREFIX = "--";
        final String BOUNDARY = "#";// 取代---------------------------7df3a01e37070c
        HttpURLConnection httpConn = null;
        BufferedInputStream bis = null;
        DataOutputStream dos = null;
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        try {
            // 实例化URL对象。调用URL有参构造方法,参数是一个url地址;
            URL urlObj = new URL(url);
            // 调用URL对象的openConnection()方法,创建HttpURLConnection对象;
            httpConn = (HttpURLConnection) urlObj.openConnection();
            // 调用HttpURLConnection对象setDoOutput(true)、setDoInput(true)、setRequestMethod("POST");
            httpConn.setDoInput(true);
            httpConn.setDoOutput(true);
            httpConn.setRequestMethod("POST");
            // 设置Http请求头信息;(Accept、Connection、Accept-Encoding、Cache-Control、Content-Type、User-Agent)
            httpConn.setUseCaches(false);
            httpConn.setRequestProperty("Connection", "Keep-Alive");
            httpConn.setRequestProperty("Accept", "*/*");
            httpConn.setRequestProperty("Accept-Encoding", "gzip, deflate");
            httpConn.setRequestProperty("Cache-Control", "no-cache");
            httpConn.setRequestProperty("Content-Type",
                    "multipart/form-data; boundary=" + BOUNDARY);
            httpConn.setRequestProperty(
                    "User-Agent",
                    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 2.0.50727; .NET CLR 3.0.04506.30)");
            // 调用HttpURLConnection对象的connect()方法,建立与服务器的真实连接;
            httpConn.connect();

            // 调用HttpURLConnection对象的getOutputStream()方法构建输出流对象;
            dos = new DataOutputStream(httpConn.getOutputStream());
            // 获取表单中上传控件之外的控件数据,写入到输出流对象(根据HttpWatch提示的流信息拼凑字符串);
            if (map != null && !map.isEmpty()) {
                for (Map.Entry<String, String> entry : map.entrySet()) {
                    String key = entry.getKey();
                    String value = map.get(key);
                    dos.writeBytes(PREFIX + BOUNDARY + NEWLINE);
                    dos.writeBytes("Content-Disposition: form-data; "
                            + "name=\"" + key + "\"" + NEWLINE);
                    dos.writeBytes(NEWLINE);
                    dos.writeBytes(URLEncoder.encode(value.toString(), charset));
                    // 或者写成:dos.write(value.toString().getBytes(charset));
                    dos.writeBytes(NEWLINE);
                }
            }

            // 获取表单中上传控件的数据,写入到输出流对象(根据HttpWatch提示的流信息拼凑字符串);
            if (body_data != null && body_data.length > 0) {
                dos.writeBytes(PREFIX + BOUNDARY + NEWLINE);
                String fileName = filePath.substring(filePath
                        .lastIndexOf(File.separatorChar) + 1);
                dos.writeBytes("Content-Disposition: form-data; " + "name=\""
                        + "uploadFile" + "\"" + "; filename=\"" + fileName
                        + "\"" + NEWLINE);
                dos.writeBytes(NEWLINE);
                dos.write(body_data);
                dos.writeBytes(NEWLINE);
            }
            dos.writeBytes(PREFIX + BOUNDARY + PREFIX + NEWLINE);
            dos.flush();

            // 调用HttpURLConnection对象的getInputStream()方法构建输入流对象;
            byte[] buffer = new byte[8 * 1024];
            int c = 0;
            // 调用HttpURLConnection对象的getResponseCode()获取客户端与服务器端的连接状态码。如果是200,则执行以下操作,否则返回null;
            if (httpConn.getResponseCode() == 200) {
                bis = new BufferedInputStream(httpConn.getInputStream());
                while ((c = bis.read(buffer)) != -1) {
                    baos.write(buffer, 0, c);
                    baos.flush();
                }
            }
            // 将输入流转成字节数组,返回给客户端。
            return new String(baos.toByteArray(), charset);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (dos != null) {
                    dos.close();
                }
                if (bis != null) {
                    bis.close();
                }
                if (baos != null) {
                    baos.close();
                }
                httpConn.disconnect();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return null;
    }

    public static byte[] streamToByte(InputStream is) {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        int c = 0;
        byte[] buffer = new byte[8 * 1024];
        try {
            while ((c = is.read(buffer)) != -1) {
                baos.write(buffer, 0, c);
                baos.flush();
            }
            return baos.toByteArray();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (baos != null) {
                    baos.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return null;
    }
}

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