安卓项目4

经历两天的琢磨，终于把android连接服务器端php，读取mysql这一块弄好了。

先说说这几天遇到的问题。

http://wenku.baidu.com/view/87ca3bfa700abb68a982fbca.html

这是我参照的资料，原先我一度认为是不能实例化ServiceLink类，后来在其中弄了好多了Log.i后发现不是这样的。

第一个遇到的问题是

HttpPost httpPost = new HttpPost(url);

 其中url一定要写http:// 这点很重要，否则就会报错

03-07 16:16:57.678: E/AndroidRuntime(517): java.lang.IllegalStateException: Target host must not be null, or set in parameters.

其次是要申请权限，在Manifest里申请。

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

 然后就是php端的了。

第一，不能有BOM头，这个可以用notepad++ 来编写无BOM文档。如果没有去掉BOM会弹出以下错误。

JSONException: java.lang.String cannot be converted to JSONObject

 第二，一定要是纯JSON输出，中文必须用utf-8，否则也会出现上面的错误。

贴一下我的JAVA代码和PHP代码

//Activity

import org.json.JSONObject;

import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class QRcodeActivity extends Activity {

	private ServiceLink servicelink =  new ServiceLink();
	private	Button loginsubmit;
	private Button logincancer;
	private TextView hostname;
	private TextView username;
	private TextView password;
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_qrcode);
		loginsubmit = (Button)findViewById(R.id.loginsubmit);
		logincancer = (Button)findViewById(R.id.logincencer);
		hostname = (TextView)findViewById(R.id.edithostname);
		username = (TextView)findViewById(R.id.editusername);
		password = (TextView)findViewById(R.id.editpassword);
		Log.i("login","Listener!");
		loginsubmit.setOnClickListener(new View.OnClickListener() {

			@Override
			public void onClick(View view) {
				// TODO Auto-generated method stub
				Log.i("login","reading JSON!");
				String hostnamestring = hostname.getText().toString();
				Log.i("string",hostnamestring);
				String usernamestring = username.getText().toString();
				Log.i("string",usernamestring);
				String passwordstring = password.getText().toString();
				Log.i("string",passwordstring);
				Log.i("login","new JSONObject!");
				JSONObject jsonobject= new JSONObject();
				Log.i("login","setURL");
				servicelink.setURL("http://210.38.160.75/QRcode.php");
				Log.i("login","serviceLogin");
				jsonobject = servicelink.serviceLogin(hostnamestring, usernamestring, passwordstring);
				Log.i("login",jsonobject.toString());
			}
		});
		

		
	}

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

}

 //ServiceLink.class

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HTTP;
import org.json.JSONException;
import org.json.JSONObject;

import android.util.Log;


public final class ServiceLink {
/*	
	功能：连接服务器
	API：link(String url);
		get(String bundle, String value);
*/
	private	String url = null;


	ServiceLink(){
		Log.i("ServiceLink", "ServiceLink");
		
	}
	public void setURL(String urll){
		this.url = urll;
		Log.i("ServiceLink",url);
	}
	public JSONObject serviceLogin(String hostname,String username, String password){
		List<NameValuePair> params = new ArrayList<NameValuePair>();
		Log.i("ServiceLink","add params to ArrayList");
		params.add(new BasicNameValuePair("operate","login"));
		params.add(new BasicNameValuePair("hostname", hostname));
		params.add(new BasicNameValuePair("username",username));
		params.add(new BasicNameValuePair("password", password));
		Log.i("ServiceLink","ready to return value from putParamsToHttp! ");
		return putParamsToHttp(params);
		
	}
	public JSONObject serviceClean(){
		List<NameValuePair> params = new ArrayList<NameValuePair>();
		params.add(new BasicNameValuePair("operate", "clean"));
		return putParamsToHttp(params);
	}
	
	public JSONObject serviceSearch(String form, String field, String value){
		List<NameValuePair> params = new ArrayList<NameValuePair>();
		params.add(new BasicNameValuePair("operate", "search"));
		params.add(new BasicNameValuePair("form", form));
		params.add(new BasicNameValuePair("field", field));
		params.add(new BasicNameValuePair("value", value));
		return putParamsToHttp(params);
	}

	public JSONObject serviceRead(String form){
		List<NameValuePair> params = new ArrayList<NameValuePair>();
		params.add(new BasicNameValuePair("operate", "read"));
		params.add(new BasicNameValuePair("form", form));
		return putParamsToHttp(params);
	}
	public JSONObject serviceRead(String form, String base, String num){
		List<NameValuePair> params = new ArrayList<NameValuePair>();
		params.add(new BasicNameValuePair("operate", "read"));
		params.add(new BasicNameValuePair("form", form));
		params.add(new BasicNameValuePair("base", base));
		params.add(new BasicNameValuePair("num", num));

		return putParamsToHttp(params);
	}
	
	public JSONObject serviceAlter(String form, String field, String id, String value){
		List<NameValuePair> params = new ArrayList<NameValuePair>();
		params.add(new BasicNameValuePair("operate", "alter"));
		params.add(new BasicNameValuePair("form", form));
		params.add(new BasicNameValuePair("field", field));
		params.add(new BasicNameValuePair("id", id));
		params.add(new BasicNameValuePair("value", value));

		return putParamsToHttp(params);
	}
	
	public JSONObject serviceDelete(String id){
		List<NameValuePair> params = new ArrayList<NameValuePair>();
		params.add(new BasicNameValuePair("operate", "delete"));
		params.add(new BasicNameValuePair("id", id));
		return putParamsToHttp(params);
	}	
	
	public JSONObject serviceInsert(String form,String device,String port,String vlan,String singleMulti, String function, String destDevice){
		List<NameValuePair> params = new ArrayList<NameValuePair>();
		params.add(new BasicNameValuePair("operate", "Insert"));
		params.add(new BasicNameValuePair("form", form));
		params.add(new BasicNameValuePair("device", device));
		params.add(new BasicNameValuePair("port", port));
		params.add(new BasicNameValuePair("vlan", vlan));
		params.add(new BasicNameValuePair("singleMulti", singleMulti));
		params.add(new BasicNameValuePair("function", function));
		params.add(new BasicNameValuePair("destDevice", destDevice));
		return putParamsToHttp(params);
	}	

	public JSONObject serviceInsert(String form,String port,String vlan,String singleMulti, String function, String destDevice){
		List<NameValuePair> params = new ArrayList<NameValuePair>();
		params.add(new BasicNameValuePair("operate", "Insert"));
		params.add(new BasicNameValuePair("form", form));
		params.add(new BasicNameValuePair("port", port));
		params.add(new BasicNameValuePair("vlan", vlan));
		params.add(new BasicNameValuePair("singleMulti", singleMulti));
		params.add(new BasicNameValuePair("function", function));
		params.add(new BasicNameValuePair("destDevice", destDevice));
		return putParamsToHttp(params);
	}	
	
	public JSONObject putParamsToHttp(List<NameValuePair> params){
		HttpPost httpPost = new HttpPost(url);
		InputStream is = null;
	    JSONObject jObj = null;
	    String json = null;
	    Log.i("ServiceLink","ready to put params to http!s");
	    
		try {
			//设置httpPost请求参数
			Log.i("ServiceLink","setEntity");
			httpPost.setEntity(new UrlEncodedFormEntity(params, HTTP.UTF_8));
			//
			Log.i("ServiceLink","execute");

			HttpResponse httpResponse = new DefaultHttpClient().execute(httpPost);
			Log.i("ServiceLink","getStatusCode");
			if(httpResponse.getStatusLine().getStatusCode() == 200){
					Log.i("ServiceLink","response ok!");
	               HttpEntity httpEntity = httpResponse.getEntity();
	                is = httpEntity.getContent(); 
	    			Log.i("ServiceLink","getContent");
			}
		} catch (UnsupportedEncodingException e) {
			// TODO Auto-generated catch block
			Log.i("ServiceLink", "Link failed --ServiceLink");
		} catch (ClientProtocolException e) {
			// TODO Auto-generated catch block
			Log.i("ServiceLink", "Link failed --ClientProtocolException");
		} catch (IOException e) {
			// TODO Auto-generated catch block
			Log.i("ServiceLink", "Link failed --IOException");
		}
	    try {
	            BufferedReader reader = new BufferedReader(new InputStreamReader(is));
	            Log.i("ServiceLink","new StringBuilder");
	            StringBuilder sb = new StringBuilder();
	            String line = null;
	            while ((line = reader.readLine()) != null) {
	                sb.append(line + "\n");
		            Log.i("ServiceLink",line);
	            }
	            is.close();
	            json = sb.toString();
	            Log.i("ServiceLink",json);

	    } catch (Exception e) {
	            Log.e("Buffer Error", "Error converting result " + e.toString());
	            Log.d("json", json.toString());
	    }

	        // try parse the string to a JSON object
	    try {
	            jObj = new JSONObject(json);
	    } catch (JSONException e) {
	            Log.e("JSON Parser", "Error parsing data " + e.toString());
	    }

	        // return JSON String
	    return jObj;

	}
}

 //php

<?php
	header("Content-Type:text/html; charset=utf-8");

	if(!isset($_COOKIE['hostname']))$hostname = "localhost";
		else $hostname = $_COOKIE['hostname'];
	if(!isset($_COOKIE['username']))$username = "root";
		else $username = $_COOKIE['username'];
	if(!isset($_COOKIE['password']))$password = "";
		else $password = $_COOKIE['password'];
	
	$true = array('success'=>'true');
	
	if(!isset($_POST['operate'])){
		print(json_encode("error():请输入操作"));
		die(mysql_error());
	}
	else{
		$operate = $_POST['operate'];
		switch ($operate){
			case "login":
				login($_POST['hostname'],$_POST['username'],$_POST['password']);
				break;
			case "clean":
				clean();
				break;
			case "search":
				search($_POST['form'], $_POST['field'], $_POST['value']);
				break;
			case "read":
				if(!isset($_POST['num']))read1($_POST['form']);
				else read2($_POST['$form'], $_POST['$base'], $_POST['$num']);
				break;
			case "alter":
				alter($_POST['form'], $_POST['field'], $_POST['id'],$_POST['value']);
				break;
			case "delete":
				delete($_POST['form'],$_POST['id']);
				break;
			case "insert":
				if(isset($_POST['device']))insert1($_POST['form'],$_POST['device'], $_POST['port'], $_POST['vlan'], $_POST['singleMulti'], $_POST['function'], $_POST['destDevice']);
				else insert2();
				break;
			default:
				print(json_encode("error():请输入操作"));
				die(mysql_error());
				
		}
	}
	
	function login($login_hostname,$login_username,$login_password){
	//登录
		global $true;
		$link = @mysql_connect($login_hostname,$login_username,$login_password);
		if(!$link){
			print(json_encode("error():数据库连接失败"));
			die(mysql_error());
		}
		mysql_query("set names utf8");
		$selected_db = mysql_select_db("qrcode");
		if(!$selected_db){
			die(mysql_error());
		}
		
		setcookie("hostname", $login_hostname, time()+ 9999999);
		setcookie("username", $login_username, time()+ 9999999);
		setcookie("password", $login_password, time()+ 9999999);
		print(json_encode($true));return "true";
	}
	
	
	function clean(){
	//清楚cookies
		mysql_close();
		setcookie("hostname", $hostname, time()- 9999999);
		setcookie("username", $username, time()- 9999999);
		setcookie("password", $password, time()- 9999999);

	}
	function search($form, $field, $value){
	//查询
	global $hostname;
	global $password;
	global $username;
		login($hostname,$username,$password);
		$sql="select * from $form where $field = $value";
		$result = mysql_query($sql);
		
		if(!$result){
			print(json_encode("error():数据库查询失败"));
			die(mysql_error());

		}
		while($e=mysql_fetch_assoc($result))
            $output[]=$e;  
        print(json_encode($output));  
		mysql_close();
		print(json_encode($true));return "true";
	}
	
	function read1($form){
		if(read2($form, 0, 5)){print(json_encode($true));return "true";}
		else die(mysql_error());
	}
	function read2($form, $base, $num){
	//读取
	global $hostname;
	global $password;
	global $username;
		login($hostname,$username,$password);

		$sql = "select * from `$form` LIMIT $base, $num";
		$result = mysql_query($sql);
		
		if(!$result){
			print(json_encode("error():数据库读取失败"));
			die(mysql_error());
		}
		
		while($e=mysql_fetch_assoc($result))
            $output[]=$e;  
        print(json_encode($output));  
		mysql_close();
		print(json_encode($true));return "true";
	}
	function alter($form, $field, $id,$value){
	//修改
	global $hostname;
	global $password;
	global $username;
		login($hostname,$username,$password);
		$sql = "UPDATE `$form` SET `$field`=$value WHERE `id` = $id";
		$result = mysql_query($sql);
		
		if(!$result){
			print(json_encode("error():数据库更新失败"));
			die(mysql_error());
		}
		print(json_encode("alter success"));
		mysql_close();
		print(json_encode($true));return "true";
	}
	function delete($form,$id){
	//删除
	global $hostname;
	global $password;
	global $username;
		login($hostname,$username,$password);
		$sql = "delete from `$form` where `$id` = $id";
		$result = mysql_query($sql);
		
		if(!$result ){
			print(json_encode("error():数据库删除失败"));
			die(mysql_error());
		}
		print(json_encode("delete success"));
		mysql_close();
		print(json_encode($true));return "true";
	}
	function insert1($form,$device, $port, $vlan, $singleMulti, $function, $destDevice){
	//插入
	global $hostname;
	global $password;
	global $username;
		login($hostname,$username,$password);
		$sql="INSERT INTO `form`(`device`, `port`, `VLAN`, `singleMultiMode`, `function`, `destDeviceOrPort`) VALUES ($device,$port,$vlan,$singleMulti,$function,$destDevice)";
		$result = mysql_query($sql);

		if(!$result ){
			print(json_encode("error():数据库插入失败"));
			die(mysql_error());
		}
		print(json_encode("insert success"));
		mysql_close();
		print(json_encode($true));return "true";
		
	}
	function insert2($form, $port, $vlan, $singleMulti, $function, $destDevice){
	//插入
	global $hostname;
	global $password;
	global $username;
		login($hostname,$username,$password);
		$sql="INSERT INTO `form`(`port`, `VLAN`, `singleMultiMode`, `function`, `destDeviceOrPort`) VALUES ($port,$vlan,$singleMulti,$function,$destDevice)";
		$result = mysql_query($sql);

		if(!$result ){
			print(json_encode("error():数据库插入失败"));
			die(mysql_error());
		}
		print(json_encode("insert success"));
		mysql_close();
		print(json_encode($true));return "true";
		
	}
?>