Android——Tomcat+MySQL+Servlet，实现将Client传入的数据写入MySQL

Android客户端将用户的注册信息上传到Tomcat Web服务器，Servlet将注册信息写入到MySQL中。

1,准备工作

(1)在MySQL中创建好要使用的数据库和数据表。

(2)设置好Tomcat的数据库连接池。

参见Tomcat数据库连接池配置

2，Android客户端Activity和Layout的设计

(1)一个简单的注册界面，sign_layout.xml

sign_layout.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:focusableInTouchMode="true"android:background="#ff6699cc"    android:orientation="vertical"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    tools:context=".MainActivity" >        <RelativeLayout        android:layout_width="fill_parent"        android:layout_height="fill_parent"        android:background="#fffffffb"        android:orientation="horizontal"        android:padding="40dp" >        <EditText            android:id="@+id/etSgAccount"            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:layout_marginTop="30dp"            android:layout_marginBottom="20dp"            android:hint="@string/Account"            android:inputType="textEmailAddress" />        <EditText            android:id="@+id/etSgPassword"            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:layout_below="@+id/etSgAccount"            android:layout_marginBottom="20dp"            android:hint="@string/Password"            android:inputType="textPassword" />         <EditText            android:id="@+id/etSgRePassword"            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:layout_below="@+id/etSgPassword"            android:layout_marginBottom="20dp"            android:hint="@string/repassword"            android:inputType="textPassword" />        <Button            android:id="@+id/btnSign"            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:layout_below="@+id/etSgRePassword"            android:background="#ff6699cc"            android:onClick="onLogin"            android:text="@string/signup"            android:textColor="#ffffffff"            android:textSize="24sp" />    RelativeLayout>LinearLayout>

(2)编写对应的Activity——SignActivity.java

package com.bnutalk.activitytest;import android.app.Activity;import android.content.Intent;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.EditText;public class SignActivity extends Activity {    private EditText username;    private EditText password;    private Button signup;    @Override    protected void onCreate(Bundle savedInstanceState)    {        super.onCreate(savedInstanceState);        setContentView(R.layout.sign_layout);        username=(EditText) findViewById(R.id.etSgAccount);        password=(EditText) findViewById(R.id.etSgPassword);        signup=(Button) findViewById(R.id.btnSign);    }    /*发起HTTP请求*/    public void onLogin(View v)    {        String url="http://172.22.140.237:8080/web/MysServlet";        new HttpThread(url, username.getText().toString(), password.getText().toString()).start();    }}

其中的重要代码是函数onLogin,它表示当按下Signup按钮时，启动Http线程，向服务器发起Http请求。

/*发起HTTP请求*/    public void onLogin(View v)    {    /*url要访问的Tomcat的Servlet地址,将ip换成Tomacat所在主机的ip*/        String url="http://172.22.140.237:8080/web/MysServlet";    /*调用访问网络的HttpThread*/        new HttpThread(url, username.getText().toString(), password.getText().toString()).start();    }

(3)新建一个Tread类——HttpTread

访问网络属于耗时操作，因此用一个单独的线程来实现。

package com.bnutalk.activitytest;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.net.HttpURLConnection;import java.net.MalformedURLException;import java.net.URL;import android.R.string;public class HttpThread extends Thread {    String url;    String username;    String password;    public HttpThread(String url, String username, String password) {        // TODO Auto-generated constructor stub        this.url = url;        this.username = username;        this.password = password;    }    private void doGet() throws IOException {        /*将username和password传给Tomcat服务器*/        url=url+"?username="+username+"&password="+password;        try {            URL httpUrl = new URL(url);            /*获取网络连接*/            HttpURLConnection conn = (HttpURLConnection) httpUrl.openConnection();            /*设置请求方法为GET方法*/            conn.setRequestMethod("GET");            /*设置访问超时时间*/            conn.setReadTimeout(5000);            BufferedReader reader=new BufferedReader(new InputStreamReader(conn.getInputStream()));            String str;            StringBuffer sb=new StringBuffer();            //读取服务器返回的信息            while((str=reader.readLine())!=null)            {                sb.append(str);            }            //把服务端返回的数据打印出来            System.out.println("result"+sb.toString());        } catch (MalformedURLException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }    /*在run中调用doGet*/    @Override    public void run() {        try {            doGet();        } catch (IOException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }}

(4)在AndroidManifest.xml中添加网络访问权限

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

如图：

3,Server和Servlet设置

(1)建立好一个server和一个web项目，在web下建立所需的Servlet

如图所示，注册用到的Servlet是MyServlet.java,请忽略LogServlet.java

(2)在web.xml中注册Servlet

<servlet>        <servlet-name>DataServiceServletservlet-name>        <servlet-class>com.imooc.servlet.MyServletservlet-class>servlet>    <servlet-mapping>        <servlet-name>DataServiceServletservlet-name>        <url-pattern>/DataServiceServleturl-pattern>servlet-mapping>

如图所示：

(3)编写MyServlet.java

package com.imooc.servlet;import java.io.IOException;import java.io.PrintWriter;import java.sql.*;import javax.naming.InitialContext;import javax.naming.NamingException;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.sql.DataSource;import org.apache.catalina.Context;import com.mysql.jdbc.Connection;import com.mysql.jdbc.ResultSet;import com.mysql.jdbc.Statement;/** * Servlet implementation class MyServlet */@WebServlet("/MyServlet")public class MyServlet extends HttpServlet {    private static final long serialVersionUID = 1L;    /**     * @see HttpServlet#HttpServlet()     */    public MyServlet() {        super();        // TODO Auto-generated constructor stub    }    /**     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse     *      response)     */    protected void doGet(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        this.doPost(request, response);    }    /**     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse     *      response)     */    protected void doPost(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {            /*获取请求的数据，并向控制台输出*/        String username = request.getParameter("username");        String password = request.getParameter("password");        PrintWriter out = response.getWriter();        System.out.println("username" + "," + username);        System.out.println("password" + "," + password);        int rs ;        String sql = "insert into bnutalk(id,username,psswd) values(3,?,?)";        /*实现向MySQL中插入username和password*/        try {            InitialContext ctx = new InitialContext();            DataSource ds = (DataSource) ctx.lookup("java:comp/env/jdbc/t1");            /*获得数据库的连接*/            java.sql.Connection conn =ds.getConnection();            conn = ds.getConnection();            /*执行sql*/            PreparedStatement ps = conn.prepareStatement(sql);            ps.setString(1, username);            ps.setString(2, password);            rs= ps.executeUpdate();        } catch (SQLException se) {            System.out.println("SQLException: " + se.getMessage());        } catch (NamingException ne) {            System.out.println("NamingException: " + ne.getMessage());        }    }}

4，运行

(1)运行web项目，run on server

(2)运行Android客户端

如图：

先看看此时数据表中的内容：

(3)注册一个用户

用户名和密码都是csdn

控制台输出：

再次查看数据表：

如果有看不懂的，可以先去补一补Servlet,Tomcat数据库连接池，MySQL，Thread这些基础知识，有个大概印象，最起码能知道其中的逻辑，大体框架，实现机制。脑海中一个框架图，再来看代码就很简单了。