第十七天 乐在其中-Android与远端之通过JSON访问SQLServer 2005数据库

           5月10日，中雨。“黑云翻墨未遮山， 白雨跳珠乱入船。卷地风来忽吹散， 望湖楼下水如天。”

       在SQLServer 2005创建数据库librarydb，供测试使用. 建立方法见第十一天博客。

      1、服务器端

          （1）工程视图

         

                   （2）AndroidServlet.java

package json.sqlserver;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;

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 com.google.gson.Gson;

@WebServlet("/AndroidServlet")
public class AndroidServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;

	static String driver = "net.sourceforge.jtds.jdbc.Driver";
	static String url = "jdbc:jtds:sqlserver://192.168.23.1:1433/librarydb";
	static String user = "sa";
	static String password = "sa";

	protected void doGet(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException {
		request.setCharacterEncoding("UTF-8");
		response.setCharacterEncoding("UTF-8");
		response.setContentType("application/json;charset=utf-8");

		List resultList = null;
		try {
			resultList = getData();
		} catch (Exception e) {
			e.printStackTrace();
		}

		Gson gson = new Gson();
		String result = gson.toJson(resultList);
		PrintWriter out = response.getWriter();
		out.write(result);
		out.flush();
		out.close();
	}

	private List getData() throws Exception {
		List resultList = new ArrayList();
		Class.forName(driver);
		Connection conn = (Connection) DriverManager.getConnection(url, user,
				password);
		Statement statement = (Statement) conn.createStatement();
		String sql = null;
		sql = "select S_Name from student";
		ResultSet rs = statement.executeQuery(sql);
		while (rs.next()) {
			resultList.add(rs.getString("S_Name"));
		}

		return resultList;

	}

	protected void doPost(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException {
		doGet(request, response);
	}
}

            （3）运行http://192.168.23.1:8080/ServletForJsonSqlserver2005/AndroidServlet
          注意：IP:192.168.23.1:8080，是WIFI共享精灵设置的虚拟的无线网卡的IP，IP自然由虚拟的无线路由分配，使用手机连接，会自动给手机分配同一网段的IP：如：192.168.23.2。

        2、手机端代码
          （1）工程视图

               （2）MainActivity.java

package com.androidjsonsqlserver;

import java.io.InputStream;
import java.util.List;

import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.json.JSONArray;

import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

public class MainActivity extends Activity {

	JSONArray jArray;
	String result = null;
	InputStream is = null;
	StringBuilder sb = null;

	public static final String HTTPCustomer = "http://192.168.23.1:8080/ServletForJsonSqlserver2005/AndroidServlet";

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		Button b1 = (Button) findViewById(R.id.button1);

		b1.setOnClickListener(new Button.OnClickListener() {

			@Override
			public void onClick(View v) {

				EditText tv = (EditText) findViewById(R.id.editView);
				// http post
				try {

					HttpClient httpclient = new DefaultHttpClient();

					// HttpGet httpget = new HttpGet(HTTPCustomer);
					HttpPost httppost = new HttpPost(HTTPCustomer);
					HttpResponse response = httpclient.execute(httppost);

					int status = response.getStatusLine().getStatusCode();
					System.out.println("status=" + status);
					result = EntityUtils.toString(response.getEntity(), "UTF-8");
				} catch (Exception e) {
					e.printStackTrace();
				}

				try {
					Gson gson = new Gson();
					List names = gson.fromJson(result,
							new TypeToken>() {
							}.getType());

					StringBuffer str = new StringBuffer();

					for (String name : names) {

						str.append(name);
					}

					tv.setText(str);
				} catch (Exception e) {

					e.printStackTrace();
				}
			}
		});
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}
}

         （3） main.xml

        （4） strings.xml

    AndroidJsonSqlserver2005
    Hello world!
    Settings

      （5） AndroidManifest.xml

             5、安卓模拟器运行结果

           6、手机运行结果-手机截屏