Android入门：封装一个HTTP请求的辅助类

类名：HttpRequestUtil

提供了如下功能：

(1)模拟GET请求；

(2)模拟POST请求；

(3)模拟文件上传请求；

(4)发送XML数据；

发送GET请求

(1)public static URLConnection sendGetRequest(String url, Map

**FormFile.java**

package com.xiazdong.netword.http.util;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;

/**
* 上传文件
*/
public class FormFile {
/* 上传文件的数据 */
private byte[] data;
private InputStream inStream;
private File file;
/* 文件名称 */
private String filname;
/* 请求参数名称*/
private String parameterName;
/* 内容类型 */
private String contentType = "application/octet-stream";

/**
* 此函数用来传输小文件
* @param filname
* @param data
* @param parameterName
* @param contentType
*/
public FormFile(String filname, byte[] data, String parameterName, String contentType) {
this.data = data;
this.filname = filname;
this.parameterName = parameterName;
if(contentType!=null) this.contentType = contentType;
}
/**
* 此函数用来传输大文件
* @param filname
* @param file
* @param parameterName
* @param contentType
*/
public FormFile(String filname, File file, String parameterName, String contentType) {
this.filname = filname;
this.parameterName = parameterName;
this.file = file;
try {
this.inStream = new FileInputStream(file);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
if(contentType!=null) this.contentType = contentType;
}

public File getFile() {
return file;
}

public InputStream getInStream() {
return inStream;
}

public byte[] getData() {
return data;
}

public String getFilname() {
return filname;
}

public void setFilname(String filname) {
this.filname = filname;
}

public String getParameterName() {
return parameterName;
}

public void setParameterName(String parameterName) {
this.parameterName = parameterName;
}

public String getContentType() {
return contentType;
}

public void setContentType(String contentType) {
this.contentType = contentType;
}

}

HttpRequestUtil.java

package com.xiazdong.netword.http.util;
import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.InetAddress;
import java.net.Socket;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

/*
* 此类用来发送HTTP请求
* */
public class HttpRequestUtil {
/**
* 发送GET请求
* @param url
* @param params
* @param headers
* @return
* @throws Exception
*/
public static URLConnection sendGetRequest(String url,
Map<String, String> params, Map<String, String> headers)
throws Exception {
StringBuilder buf = new StringBuilder(url);
Set<Entry<String, String>> entrys = null;
// 如果是GET请求，则请求参数在URL中
if (params != null && !params.isEmpty()) {
buf.append("?");
entrys = params.entrySet();
for (Map.Entry<String, String> entry : entrys) {
buf.append(entry.getKey()).append("=")
.append(URLEncoder.encode(entry.getValue(), "UTF-8"))
.append("&");
}
buf.deleteCharAt(buf.length() - 1);
}
URL url1 = new URL(buf.toString());
HttpURLConnection conn = (HttpURLConnection) url1.openConnection();
conn.setRequestMethod("GET");
// 设置请求头
if (headers != null && !headers.isEmpty()) {
entrys = headers.entrySet();
for (Map.Entry<String, String> entry : entrys) {
conn.setRequestProperty(entry.getKey(), entry.getValue());
}
}
conn.getResponseCode();
return conn;
}
/**
* 发送POST请求
* @param url
* @param params
* @param headers
* @return
* @throws Exception
*/
public static URLConnection sendPostRequest(String url,
Map<String, String> params, Map<String, String> headers)
throws Exception {
StringBuilder buf = new StringBuilder();
Set<Entry<String, String>> entrys = null;
// 如果存在参数，则放在HTTP请求体，形如name=aaa&age=10
if (params != null && !params.isEmpty()) {
entrys = params.entrySet();
for (Map.Entry<String, String> entry : entrys) {
buf.append(entry.getKey()).append("=")
.append(URLEncoder.encode(entry.getValue(), "UTF-8"))
.append("&");
}
buf.deleteCharAt(buf.length() - 1);
}
URL url1 = new URL(url);
HttpURLConnection conn = (HttpURLConnection) url1.openConnection();
conn.setRequestMethod("POST");
conn.setDoOutput(true);
OutputStream out = conn.getOutputStream();
out.write(buf.toString().getBytes("UTF-8"));
if (headers != null && !headers.isEmpty()) {
entrys = headers.entrySet();
for (Map.Entry<String, String> entry : entrys) {
conn.setRequestProperty(entry.getKey(), entry.getValue());
}
}
conn.getResponseCode(); // 为了发送成功
return conn;
}
/**
* 直接通过HTTP协议提交数据到服务器,实现如下面表单提交功能:
*   <FORM METHOD=POST ACTION="http://192.168.0.200:8080/ssi/fileload/test.do" enctype="multipart/form-data">
<INPUT TYPE="text" NAME="name">
<INPUT TYPE="text" NAME="id">
<input type="file" name="imagefile"/>
<input type="file" name="zip"/>
</FORM>
* @param path 上传路径(注：避免使用localhost或127.0.0.1这样的路径测试，因为它会指向手机模拟器，你可以使用http://www.itcast.cn或http://192.168.1.10:8080这样的路径测试)
* @param params 请求参数 key为参数名,value为参数值
* @param file 上传文件
*/
public static boolean uploadFiles(String path, Map<String, String> params, FormFile[] files) throws Exception{
final String BOUNDARY = "---------------------------7da2137580612"; //数据分隔线
final String endline = "--" + BOUNDARY + "--\r\n";//数据结束标志

int fileDataLength = 0;
if(files!=null&&files.length!=0){
for(FormFile uploadFile : files){//得到文件类型数据的总长度
StringBuilder fileExplain = new StringBuilder();
fileExplain.append("--");
fileExplain.append(BOUNDARY);
fileExplain.append("\r\n");
fileExplain.append("Content-Disposition: form-data;name=\""+ uploadFile.getParameterName()+"\";filename=\""+ uploadFile.getFilname() + "\"\r\n");
fileExplain.append("Content-Type: "+ uploadFile.getContentType()+"\r\n\r\n");
fileExplain.append("\r\n");
fileDataLength += fileExplain.length();
if(uploadFile.getInStream()!=null){
fileDataLength += uploadFile.getFile().length();
}else{
fileDataLength += uploadFile.getData().length;
}
}
}
StringBuilder textEntity = new StringBuilder();
if(params!=null&&!params.isEmpty()){
for (Map.Entry<String, String> entry : params.entrySet()) {//构造文本类型参数的实体数据
textEntity.append("--");
textEntity.append(BOUNDARY);
textEntity.append("\r\n");
textEntity.append("Content-Disposition: form-data; name=\""+ entry.getKey() + "\"\r\n\r\n");
textEntity.append(entry.getValue());
textEntity.append("\r\n");
}
}
//计算传输给服务器的实体数据总长度
int dataLength = textEntity.toString().getBytes().length + fileDataLength +  endline.getBytes().length;

URL url = new URL(path);
int port = url.getPort()==-1 ? 80 : url.getPort();
Socket socket = new Socket(InetAddress.getByName(url.getHost()), port);
OutputStream outStream = socket.getOutputStream();
//下面完成HTTP请求头的发送
String requestmethod = "POST "+ url.getPath()+" HTTP/1.1\r\n";
outStream.write(requestmethod.getBytes());
String accept = "Accept: image/gif, image/jpeg, image/pjpeg, image/pjpeg, application/x-shockwave-flash, application/xaml+xml, application/vnd.ms-xpsdocument, application/x-ms-xbap, application/x-ms-application, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*\r\n";
outStream.write(accept.getBytes());
String language = "Accept-Language: zh-CN\r\n";
outStream.write(language.getBytes());
String contenttype = "Content-Type: multipart/form-data; boundary="+ BOUNDARY+ "\r\n";
outStream.write(contenttype.getBytes());
String contentlength = "Content-Length: "+ dataLength + "\r\n";
outStream.write(contentlength.getBytes());
String alive = "Connection: Keep-Alive\r\n";
outStream.write(alive.getBytes());
String host = "Host: "+ url.getHost() +":"+ port +"\r\n";
outStream.write(host.getBytes());
//写完HTTP请求头后根据HTTP协议再写一个回车换行
outStream.write("\r\n".getBytes());
//把所有文本类型的实体数据发送出来
outStream.write(textEntity.toString().getBytes());
//把所有文件类型的实体数据发送出来
if(files!=null&&files.length!=0){
for(FormFile uploadFile : files){
StringBuilder fileEntity = new StringBuilder();
fileEntity.append("--");
fileEntity.append(BOUNDARY);
fileEntity.append("\r\n");
fileEntity.append("Content-Disposition: form-data;name=\""+ uploadFile.getParameterName()+"\";filename=\""+ uploadFile.getFilname() + "\"\r\n");
fileEntity.append("Content-Type: "+ uploadFile.getContentType()+"\r\n\r\n");
outStream.write(fileEntity.toString().getBytes());
if(uploadFile.getInStream()!=null){
byte[] buffer = new byte[1024];
int len = 0;
while((len = uploadFile.getInStream().read(buffer, 0, 1024))!=-1){
outStream.write(buffer, 0, len);
}
uploadFile.getInStream().close();
}else{
outStream.write(uploadFile.getData(), 0, uploadFile.getData().length);
}
outStream.write("\r\n".getBytes());
}
}
//下面发送数据结束标志，表示数据已经结束
outStream.write(endline.getBytes());
BufferedReader reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
if(reader.readLine().indexOf("200")==-1){//读取web服务器返回的数据，判断请求码是否为200，如果不是200，代表请求失败
return false;
}
outStream.flush();
outStream.close();
reader.close();
socket.close();
return true;
}
/**
* 提交数据到服务器
* @param path 上传路径(注：避免使用localhost或127.0.0.1这样的路径测试，因为它会指向手机模拟器，你可以使用http://www.itcast.cn或http://192.168.1.10:8080这样的路径测试)
* @param params 请求参数 key为参数名,value为参数值
* @param file 上传文件
*/
public static boolean uploadFile(String path, Map<String, String> params, FormFile file) throws Exception{
return uploadFiles(path, params, new FormFile[]{file});
}
/**
* 将输入流转为字节数组
* @param inStream
* @return
* @throws Exception
*/
public static byte[] read2Byte(InputStream inStream)throws Exception{
ByteArrayOutputStream outSteam = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int len = 0;
while( (len = inStream.read(buffer)) !=-1 ){
outSteam.write(buffer, 0, len);
}
outSteam.close();
inStream.close();
return outSteam.toByteArray();
}
/**
* 将输入流转为字符串
* @param inStream
* @return
* @throws Exception
*/
public static String read2String(InputStream inStream)throws Exception{
ByteArrayOutputStream outSteam = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int len = 0;
while( (len = inStream.read(buffer)) !=-1 ){
outSteam.write(buffer, 0, len);
}
outSteam.close();
inStream.close();
return new String(outSteam.toByteArray(),"UTF-8");
}
/**
* 发送xml数据
* @param path 请求地址
* @param xml xml数据
* @param encoding 编码
* @return
* @throws Exception
*/
public static byte[] postXml(String path, String xml, String encoding) throws Exception{
byte[] data = xml.getBytes(encoding);
URL url = new URL(path);
HttpURLConnection conn = (HttpURLConnection)url.openConnection();
conn.setRequestMethod("POST");
conn.setDoOutput(true);
conn.setRequestProperty("Content-Type", "text/xml; charset="+ encoding);
conn.setRequestProperty("Content-Length", String.valueOf(data.length));
conn.setConnectTimeout(5 * 1000);
OutputStream outStream = conn.getOutputStream();
outStream.write(data);
outStream.flush();
outStream.close();
if(conn.getResponseCode()==200){
return read2Byte(conn.getInputStream());
}
return null;
}
//测试函数
public static void main(String args[]) throws Exception {
Map<String, String> params = new HashMap<String, String>();
params.put("name", "xiazdong");
params.put("age", "10");
HttpURLConnection conn = (HttpURLConnection) HttpRequestUtil
.sendGetRequest(
"http://192.168.0.103:8080/Server/PrintServlet",
params, null);
int code = conn.getResponseCode();
InputStream in = conn.getInputStream();
byte[]data = read2Byte(in);
}
}

测试代码：

Map<String,String> params = new HashMap<String,String>();
params.put("name", name.getText().toString());
params.put("age", age.getText().toString());
HttpURLConnection conn = (HttpURLConnection) HttpRequestUtil.sendGetRequest("http://192.168.0.103:8080/Server/PrintServlet", params, null);

文件上传测试代码：

FormFile formFile = new FormFile(file.getName(), file, "document", "text/plain");
boolean isSuccess = HttpRequestUtil.uploadFile("http://192.168.0.103:8080/Server/FileServlet", null, formFile);