安卓向服务器发送数据和服务器接收数据全过程

注意：如果打开输出流了 客户端的请求方法是GET，就会请求到服务器的POST方法去

安卓端：

package com.example.k.servletdemo;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.View;
import android.widget.Button;

import android.widget.TextView;

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLDecoder;
import java.net.URLEncoder;

public class MainActivity extends Activity {
private final int GETVALUE = 0,POSTVALUE = 1;
Button sendGET, sendPOST;
TextView t, sendPOSTtextView;
String str = "梁嘉亮";
String str1;
Handler handler = new Handler() {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case GETVALUE:
try {
msg.obj = URLDecoder.decode(msg.obj + "", "UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
t.setText("" + msg.obj);
break;
case POSTVALUE:
sendPOSTtextView.setText("" + msg.obj);
break;
default:
break;
}
}
};

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.layout);
t = (TextView) findViewById(R.id.textView);
sendPOSTtextView = (TextView) findViewById(R.id.textView2);
sendPOST = (Button) findViewById(R.id.button1);
sendGET = (Button) findViewById(R.id.button);
sendGET.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
new Thread(new Runnable() {
@Override
public void run() {
HttpURLConnection connection;
try {
//用GET方法向服务器传送数据，在链接里面传值
str1 = URLEncoder.encode(str, "UTF-8");
URL url = new URL("http://120.27.103.151:8088/JWebDemoByIDE/MyServlet?name=" + str1 + "&age=23");
connection = (HttpURLConnection) url.openConnection();
connection.setReadTimeout(5000);
connection.setRequestMethod("GET");
connection.setRequestProperty("charset", "UTF-8");
connection.setConnectTimeout(5000);
connection.setDoInput(true);
if (connection.getResponseCode() == 200) {
InputStream in = connection.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(in));
StringBuilder s = new StringBuilder();
String line;
while ((line = reader.readLine()) != null) {
s.append(line);
}
reader.close();
Message message = new Message();
message.what = GETVALUE;
message.obj = s.toString();
handler.sendMessage(message);
}
} catch (Exception e) {
Log.i("ok", "有错误！");
}
}
}).start();
}
});
sendPOST.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
new Thread(new Runnable() {
@Override
public void run() {
try {
URL url = new URL("http://120.27.103.151:8088/JWebDemoByIDE/MyServlet");
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("POST");
connection.setConnectTimeout(5000);
connection.setReadTimeout(5000);
connection.setRequestProperty("charset", "UTF-8");
connection.setDoOutput(true);
DataOutputStream out = new DataOutputStream(connection.getOutputStream());
//向服务器传送数据
out.writeBytes("Im Liang Jia Liang!");
if (connection.getResponseCode() == 200) {
InputStream in = connection.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(in));
StringBuilder s = new StringBuilder();
String line;
//读取服务器返回的数据
while ((line = reader.readLine()) != null) {
s.append(line);
}
Message message = new Message();
message.what = POSTVALUE;
message.obj = s.toString();
handler.sendMessage(message);
reader.close();
}
out.close();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}).start();
}
});
}
}

记得要声明一下网络权限：

<?xml version="1.0" encoding="UTF-8"?>

<manifest package="com.example.k.servletdemo" xmlns:android="http://schemas.android.com/apk/res/android">

<uses-permission android:name="android.permission.INTERNET"/>

<application android:theme="@style/AppTheme" android:supportsRtl="true" android:label="@string/app_name" android:icon="@mipmap/ic_launcher" android:allowBackup="true">

<activity android:name=".MainActivity">

<intent-filter>

<action android:name="android.intent.action.MAIN"/>

<category android:name="android.intent.category.LAUNCHER"/>

</intent-filter>

</activity>

</application>

</manifest>

布局文件：

<?xml version="1.0" encoding="UTF-8"?>

<LinearLayout android:layout_height="match_parent" android:layout_width="match_parent" android:orientation="vertical" xmlns:android="http://schemas.android.com/apk/res/android">

<Button android:layout_height="wrap_content" android:layout_width="match_parent" android:text="sendGET" android:id="@+id/button"/>

<TextView android:layout_height="wrap_content" android:layout_width="wrap_content" android:id="@+id/textView"/>

<Button android:layout_height="wrap_content" android:layout_width="match_parent" android:text="sendPOST" android:id="@+id/button1"/>

<TextView android:layout_height="wrap_content" android:layout_width="wrap_content" android:id="@+id/textView2"/>

</LinearLayout>

以下是服务器端：（服务器用的是tomcat，虚拟主机是阿里云的ECS）

package com.iotek.jee.servlet;

import java.io.BufferedReader;
import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class MyServlet extends HttpServlet {
private static final long serialVersionUID = -9122125709896866661L;
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//获取http://120.27.103.151:8088/JWebDemoByIDE/MyServlet?name=liangjialiang 问号后面的值
String name = req.getParameter("name");
String age = req.getParameter("age");
resp.getWriter().write(name);
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
BufferedReader b =  req.getReader();
String line;
StringBuilder s = new StringBuilder();
while((line = b.readLine())!=null){
s.append(line);
}
resp.getWriter().write(s.toString());
}
@Override
protected void doDelete(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

}
@Override
protected void doPut(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

}
}

服务器web.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
<display-name>JWebDemoByIDE</display-name>
<servlet>
<servlet-name>MyServlet</servlet-name>
<servlet-class>com.iotek.jee.servlet.MyServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>MyServlet</servlet-name>
<url-pattern>/MyServlet</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
</web-app>

服务器就两个文件如下图：



运行效果图如下：