Android-向服务器提交数据（GET-POST-AsyncHttpClient）

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:orientation="vertical">

<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="请输入账号"
android:id="@+id/et_main_uname"/>
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="请输入密码"
android:id="@+id/et_main_upass"/>
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="登录（get）"
android:onClick="loginGet"/>
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="登录（post）"
android:onClick="loginPost"/>
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="登录(AsyncHttpClient)"
android:onClick="loginAsyncHttpClient"
/>
</LinearLayout>

在Activity里面提交数据，在点击事件里面，我们只能获取输入框的值，而其他的操作我们就需要写到子线程中去,POST提交数据，点击事件和GET的一样，只是在参数的地方，我们需要多添加一个类型，为了区分在doInBackground方法里面，我们需要先判断是哪种类型的提交方式，然后把POST方法里多出来的那两个头部内容添加进去，再把内容提交服务器，就可以了,还有一种第三方网络请求框架AsyncHttpClient我们先把android-async-http-1.4.4.jar下到本地，然后拷到项目里,因为HttpClient有导致一些小问题，所以我们需要在Gradle的版本前添加一句useLibrary
'org.apache.http.legacy'在点击事件里面写提交数据，在httpClient.post方法里面，带来地址，和参数，还有一个Handler,然后重写Handler的两个方法即可。

package com.zking.administrator.g160628_android32_commitdata;

import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

import com.loopj.android.http.AsyncHttpClient;
import com.loopj.android.http.RequestParams;
import com.loopj.android.http.TextHttpResponseHandler;

import org.apache.http.Header;

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

public class MainActivity extends AppCompatActivity {

private EditText et_main_uname;
private EditText et_main_upass;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
et_main_uname = (EditText) findViewById(R.id.et_main_uname);
et_main_upass = (EditText) findViewById(R.id.et_main_upass);
}
//get方法
public void loginGet(View view){
//账号
String uname=et_main_uname.getText().toString();
//密码
String upass=et_main_upass.getText().toString();
//路径(Android端要调用.do/servlet)
String path="http://193.168.3.70:8080/Web_server/login.do";
new MyGetTask().execute(uname,upass,path);//execute中的object是一个可变数组
}
/**
* 一般我们都不支持用get提交
*/
class MyGetTask extends AsyncTask{

@Override
protected Object doInBackground(Object[] params) {
String uname=params[0].toString();
String upass=params[1].toString();
String path=params[2].toString();
//把账号密码提交到服务器
try {
URL url=new URL(path+"?uname="+uname+"&upass="+upass);
HttpURLConnection connection= (HttpURLConnection) url.openConnection();
//设置请求方式
connection.setRequestMethod("Get");
//超时
connection.setConnectTimeout(5000);
//判断结果码
if(connection.getResponseCode()==200){
InputStream is=connection.getInputStream();
BufferedReader br=new BufferedReader(new InputStreamReader(is));
String s=br.readLine();
ret
a81d
urn s;
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}

@Override
protected void onPostExecute(Object o) {
super.onPostExecute(o);
String s= (String) o;
Toast.makeText(MainActivity.this, s, Toast.LENGTH_SHORT).show();
}

//post方法
public void loginPost(View view){
//账号
String uname=et_main_uname.getText().toString();
//密码
String upass=et_main_upass.getText().toString();
//路径(Android端要调用.do/servlet)
String path="http://193.168.3.70:8080/Web_server/login.do";
new MyPostTask().execute(uname,upass,path);//execute中的object是一个可变数组
}

class MyPostTask extends AsyncTask{

@Override
protected Object doInBackground(Object[] params) {
String uname=params[0].toString();
String upass=params[1].toString();
String path=params[2].toString();
//把账号密码提交到服务器
try {
URL url=new URL(path);
HttpURLConnection connection= (HttpURLConnection) url.openConnection();
//设置请求方式
connection.setRequestMethod("POST");
//超时时间
connection.setConnectTimeout(5000);
//字符串拼接
String s="uname="+uname+"&upass="+upass;
//添加请求头(做Java程序要知道如何给Android程序员去写接口文档)
connection.setRequestProperty("Content-Length",s.length()+"");
connection.setRequestProperty("Content-Type","application/x-www-form-urlencoded");
connection.setDoOutput(true);//允许对外输出数据
OutputStream os=connection.getOutputStream();//写
os.write(s.getBytes());
//判断结果码
if(connection.getResponseCode()==200){
InputStream is=connection.getInputStream();
BufferedReader br=new BufferedReader(new InputStreamReader(is));
String str=br.readLine();
return str;
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}

@Override
protected void onPostExecute(Object o) {
super.onPostExecute(o);
String str= (String) o;
Toast.makeText(MainActivity.this, str, Toast.LENGTH_SHORT).show();
}
}

//AsyncHttpClient第三方
public void loginAsyncHttpClient(View view){
String uname=et_main_uname.getText().toString();
String upass=et_main_upass.getText().toString();
String path="http://193.168.3.70:8080/Web_server/login.do";

AsyncHttpClient ahc=new AsyncHttpClient();
RequestParams params=new RequestParams();
params.put("uname",uname);
params.put("upass",upass);
ahc.post(MainActivity.this,path,params,new TextHttpResponseHandler(){
@Override
public void onFailure(int statusCode, Header[] headers, String responseBody, Throwable error) {
super.onFailure(statusCode, headers, responseBody, error);
}

@Override
public void onSuccess(int statusCode, Header[] headers, String responseBody) {
super.onSuccess(statusCode, headers, responseBody);
Toast.makeText(MainActivity.this, responseBody, Toast.LENGTH_SHORT).show();
}
});
}
}
}