Android 使用HTTP（get和post）方式登陆服务器

package com.wuyou.submittoserver;

import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.text.TextUtils;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;

public class MainActivity extends ActionBarActivity {

private static final int OK = 200;
private EditText usernameEditText;
private EditText passwrodEditText;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

usernameEditText = (EditText) findViewById(R.id.username);
passwrodEditText = (EditText) findViewById(R.id.password);
}

/**
* post方法多了三个东西：
* ①请求的表单类型
* ②请求的数据长度
* ③请求的数据并且写给服务器
*/
public void post(View view) {
final String username = usernameEditText.getText().toString().trim();
final String password = passwrodEditText.getText().toString().trim();
//Android默认模拟器外部的地址为10.0.2.2，而不是localhost和127.0.0.1
final String serverPath = "http://10.0.2.2:8080/LoginServlet";
if (TextUtils.isEmpty(username) || TextUtils.isEmpty(password)) {
//给出提示：账号密码不许为空
} else {
new Thread(new Runnable() {
@Override
public void run() {
try {
//向服务器请求的数据
String data = "username=" + URLEncoder.encode(username,"UTF-8") + "&password=" + URLEncoder.encode(password,"UTF-8");
URL url = new URL(serverPath);
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setConnectTimeout(3000);
httpURLConnection.setDoOutput(true);//打开输出流，以便向服务器提交数据
//设置请求体的类型是文本类型
httpURLConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
//设置请求体的长度
httpURLConnection.setRequestProperty("Content-Length", String.valueOf(data.length()));
//获得输出流，向服务器写入数据
OutputStream outputStream = httpURLConnection.getOutputStream();
outputStream.write(data.getBytes());

int responseCode = httpURLConnection.getResponseCode();
if (200 == responseCode) {
InputStream inputStream = httpURLConnection.getInputStream();
final String responseMsg = StreamTool.getString(inputStream);
runOnUiThread(new Runnable() {
@Override
public void run() {
Toast.makeText(MainActivity.this, responseMsg, Toast.LENGTH_LONG).show();
}
});
} else {
System.out.println("responseCode = " + responseCode);
//连接服务器出错，错误代码为：responseCode 根据代码值告诉用户出错的原因
//....
}
} catch (Exception e) {
e.printStackTrace();
}
}
}).start();
}
}

public void get(View view) {
final String username = usernameEditText.getText().toString().trim();
final String password = passwrodEditText.getText().toString().trim();
//Android默认模拟器外部的地址为10.0.2.2，而不是localhost和127.0.0.1
final String serverPath = "http://10.0.2.2:8080/LoginServlet";
if (TextUtils.isEmpty(username) || TextUtils.isEmpty(password)) {
//给出提示：账号密码不许为空
} else {
new Thread(new Runnable() {
@Override
public void run() {
try {
//使用GET方式请求服务器只能这样
URL url = new URL(serverPath + "?username=" + URLEncoder.encode(username,"UTF-8") + "&password=" + URLEncoder.encode(password,"UTF-8"));
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
httpURLConnection.setRequestMethod("GET");
httpURLConnection.setConnectTimeout(5000);
httpURLConnection.setRequestProperty("User-Agent", "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:22.0) Gecko/20100101 Firefox/22.0");
int responseCode = httpURLConnection.getResponseCode();
if (200 == responseCode) {
InputStream inputStream = httpURLConnection.getInputStream();
final String responseMsg = StreamTool.getString(inputStream);
runOnUiThread(new Runnable() {
@Override
public void run() {
Toast.makeText(MainActivity.this, responseMsg, Toast.LENGTH_LONG).show();
}
});
} else {
System.out.println("responseCode = " + responseCode);
//连接服务器出错，错误代码为：responseCode 根据代码值告诉用户出错的原因
//....
}
} catch (Exception e) {
e.printStackTrace();
}
}
}).start();
}
}
}

class StreamTool {
public static String getString(InputStream inputStream) throws IOException {
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
byte[] buf = new byte[1024];
int length;
while((length = inputStream.read(buf)) >0) {
byteArrayOutputStream.write(buf, 0 ,length);
}
byte[] stringBytes = byteArrayOutputStream.toByteArray();
String str = new String(stringBytes);
return str;
}
}