2.2 常用工具类 网络 支撑 JSON
网络可以选择例如okHttp,或者retrofit，也可以使用httpclient等。
httpUtils:
package com.qianfeng.loaderdemo.utils;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.HashMap;
import java.util.Set;
import java.util.zip.GZIPInputStream;
/**
* Created with IntelliJ IDEA.
* User: vhly[FR]
* Date: 15/11/23
* Email: [email protected]
*/
public final class HttpUtils {
public static final int CONNECT_TIMEOUT = 5000;
private HttpUtils() {
}
public static byte[] doGet(String url) {
return doGet(url, null);
}
public static byte[] doGet(String url, HashMap<String, String> headers) {
byte[] ret = null;
if (url != null) {
HttpURLConnection conn = null;
try {
URL u = new URL(url);
conn = (HttpURLConnection) u.openConnection();
conn.setRequestMethod("GET");
conn.setConnectTimeout(CONNECT_TIMEOUT);
setCommonHeaders(conn);
if (headers != null) {
Set<String> keySet = headers.keySet();
for (String key : keySet) {
String value = headers.get(key);
conn.setRequestProperty(key, value);
}
}
conn.connect();
int responseCode = conn.getResponseCode();
if (responseCode == 200) {
ret = processResponse(conn);
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
StreamUtils.close(conn);
//noinspection UnusedAssignment
conn = null;
}
}
return ret;
}
private static byte[] processResponse(HttpURLConnection conn) {
byte[] ret = null;
InputStream inputStream = null;
try {
String contentEncoding = conn.getContentEncoding();
inputStream = conn.getInputStream();
if ("gzip".equals(contentEncoding)) {
inputStream = new GZIPInputStream(inputStream);
}
ret = StreamUtils.readStream(inputStream);
} catch (IOException e) {
e.printStackTrace();
} finally {
StreamUtils.close(inputStream);
}
return ret;
}
private static void setCommonHeaders(HttpURLConnection conn) {
if (conn != null) {
conn.setRequestProperty("Connection", "Keep-Alive");
conn.setRequestProperty("Accept-Encoding", "gzip");
conn.setRequestProperty("Accept-Charset", "UTF-8");
conn.setRequestProperty("Accept", "application/*, text/*, */*");
conn.setRequestProperty("X-Client", "Common HttpUtils");
}
}
}
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
StreamUtils.java:
package com.qianfeng.loaderdemo.utils;
import java.io.*;
import java.net.HttpURLConnection;
/**
* Created with IntelliJ IDEA.
* User: vhly[FR]
* Date: 15/11/24
* Email: [email protected]
*/
public final class StreamUtils {
private StreamUtils() {
}
public static void close(Object stream) {
if (stream != null) {
try {
if (stream instanceof InputStream) {
((InputStream) stream).close();
} else if (stream instanceof OutputStream) {
((OutputStream) stream).close();
} else if (stream instanceof Reader) {
((Reader) stream).close();
} else if (stream instanceof Writer) {
((Writer) stream).close();
} else if (stream instanceof HttpURLConnection) {
((HttpURLConnection) stream).disconnect();
}
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
public static byte[] readStream(InputStream in) {
byte[] ret = null;
if (in != null) {
ByteArrayOutputStream bout = new ByteArrayOutputStream();
try {
long len = readStream(in, bout);
if (len > 0) {
ret = bout.toByteArray();
}
} catch (IOException ioe) {
ioe.printStackTrace();
}
close(bout);
//noinspection UnusedAssignment
bout = null;
}
return ret;
}
public static long readStream(InputStream in, OutputStream out) throws IOException {
long ret = 0;
if (in != null && out != null) {
byte[] buf = new byte[1024];
int len;
while (true) {
len = in.read(buf);
if (len == -1) {
break;
}
out.write(buf, 0, len);
ret += len;
}
//noinspection UnusedAssignment
buf = null;
}
return ret;
}
}