无论是用哪种方式使Android与web后台进行数据交互,都需要在eclipes中写一个完整的操作流程,在这里,我是写了一个登录。(没有从数据库进行判断,而是直接把用户名和密码定死了),下面就是我的后台web端。你可以根据你的不同需求在jsp界面用你所需要的提交方式来写
login,jsp:
- <%@ page language="java" contentType="text/html; charset=UTF-8"
- pageEncoding="UTF-8"%>
- <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
- <html>
- <head>
- <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
- <title>Insert title here</title>
- </head>
- <body>
- <!-- <form action="login.do" method="get">
- 用户名:<input type="text" name="uname"/><br>
- 密码:<input type="password" name="upass"/><br>
- <input type="submit" value="登录"/>
- </form> -->
-
- <form action="login.do" method="post">
- 用户名:<input type="text" name="uname"/><br>
- 密码:<input type="password" name="upass"/><br>
- <input type="submit" value="登录"/>
- </form>
- </body>
- </html>
LoginServlet:
- package com.lxj.servlet;
-
- import java.io.IOException;
- import java.io.PrintWriter;
-
- import javax.servlet.ServletException;
- import javax.servlet.http.HttpServlet;
- import javax.servlet.http.HttpServletRequest;
- import javax.servlet.http.HttpServletResponse;
-
- public class Login extends HttpServlet{
-
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- @Override
- protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
- String uname=req.getParameter("uname");
- String upass=req.getParameter("upass");
-
- String a=null;
- if("admin".equals(uname) && "123".equals(upass)){
- a="succes";
- System.out.println(a);
- }else{
- a="fail";
- System.out.println(a);
- }
- PrintWriter pw=resp.getWriter();
- pw.write(a);
- pw.close();
- }
- }
最后,还要记得在web.xml里面配置跳转路径
- <servlet>
- <servlet-name>login</servlet-name>
- <servlet-class>com.lxj.servlet.Login</servlet-class>
- </servlet>
-
- <servlet-mapping>
- <servlet-name>login</servlet-name>
- <url-pattern>/login.do</url-pattern>
- </servlet-mapping>
第一:GET提交方式:
activity_main.xml:
- <?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"
- tools:context="com.example.android_getandpost.MainActivity">
-
- <EditText
- android:layout_width="match_parent"
- android:layout_height="wrap_content"
- android:hint="请输入用户名"
- android:id="@+id/uname"
- />
-
- <EditText
- android:layout_width="match_parent"
- android:layout_height="wrap_content"
- android:hint="请输入密码"
- android:id="@+id/upass"
- />
-
- <Button
- android:layout_width="match_parent"
- android:layout_height="wrap_content"
- android:text="登陆(Get)"
- android:onClick="LoginGet"
- />
-
- </LinearLayout>
MainActivity:
- package com.example.android_getandpost;
-
- import android.os.AsyncTask;
- import android.support.v7.app.AppCompatActivity;
- import android.os.Bundle;
- import android.util.Log;
- import android.view.View;
- import android.widget.EditText;
- import android.widget.Toast;
-
- import java.io.BufferedReader;
- import java.io.IOException;
- import java.io.InputStream;
- import java.io.InputStreamReader;
- import java.net.HttpURLConnection;
- import java.net.MalformedURLException;
- import java.net.URL;
-
- public class MainActivity extends AppCompatActivity {
-
- private EditText uname;
- private EditText upass;
-
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.activity_main);
-
- uname = (EditText) findViewById(R.id.uname);
-
- upass = (EditText) findViewById(R.id.upass);
- }
-
- public void LoginGet(View view){
-
- String name=uname.getText().toString();
-
- String pass=upass.getText().toString();
-
- String path="http://193.168.3.16:8080/Login/login.do";
-
- new getTask().execute(name,pass,path);
- }
-
- class getTask extends AsyncTask {
-
- @Override
- protected Object doInBackground(Object[] params) {
-
- String name = params[0].toString();
- String pass = params[1].toString();
- String path = params[2].toString();
-
- try {
-
- URL url = new URL(path + "?uname=" + name + "&upass=" + pass);
-
- HttpURLConnection conn = (HttpURLConnection) url.openConnection();
-
- conn.setRequestMethod("GET");
-
- conn.setConnectTimeout(5000);
-
- int code = conn.getResponseCode();
- if (code == 200) {
-
- InputStream is = conn.getInputStream();
-
- BufferedReader br = new BufferedReader(new InputStreamReader(is));
-
- String s = br.readLine();
-
- return 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();
- }
- }
-
- }
第二:POST提交方式:
activity_main2.xml:
- package com.example.android_getandpost;
-
- import android.os.AsyncTask;
- import android.support.v7.app.AppCompatActivity;
- import android.os.Bundle;
- import android.util.Log;
- import android.view.View;
- import android.widget.EditText;
- import android.widget.Toast;
-
- import java.io.BufferedReader;
- import java.io.IOException;
- import java.io.InputStream;
- import java.io.InputStreamReader;
- import java.net.HttpURLConnection;
- import java.net.MalformedURLException;
- import java.net.URL;
-
- public class MainActivity extends AppCompatActivity {
-
- private EditText uname;
- private EditText upass;
-
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.activity_main);
- //获取用户名的id
- uname = (EditText) findViewById(R.id.uname);
- //获取密码的id
- upass = (EditText) findViewById(R.id.upass);
- }
-
- public void LoginGet(View view){
- //获取用户名的值
- String name=uname.getText().toString();
- //获取密码的值
- String pass=upass.getText().toString();
- //获取网络上的servlet路径
- String path="http://193.168.3.16:8080/Login/login.do";
- //调用getTask,把获取到的用户名,密码与路径放入方法中
- new getTask().execute(name,pass,path);
- }
-
- class getTask extends AsyncTask {
-
- @Override
- protected Object doInBackground(Object[] params) {
- //依次获取用户名,密码与路径
- String name = params[0].toString();
- String pass = params[1].toString();
- String path = params[2].toString();
-
- try {
- //获取网络上get方式提交的整个路径
- URL url = new URL(path + "?uname=" + name + "&upass=" + pass);
- //打开网络连接
- HttpURLConnection conn = (HttpURLConnection) url.openConnection();
- //设置提交方式
- conn.setRequestMethod("GET");
- //设置网络超时时间
- conn.setConnectTimeout(5000);
- //获取结果码
- int code = conn.getResponseCode();
- if (code == 200) {
- //用io流与web后台进行数据交互
- InputStream is = conn.getInputStream();
- //字节流转字符流
- BufferedReader br = new BufferedReader(new InputStreamReader(is));
- //读出每一行的数据
- String s = br.readLine();
- //返回读出的每一行的数据
- return s;
- }
- } catch (MalformedURLException e) {
- e.printStackTrace();
- } catch (IOException e) {
- e.printStackTrace();
- }
- return null;
- }
- @Override
- protected void onPostExecute(Object o) {
- super.onPostExecute(o);
- //获取Android studio与web后台数据交互获得的值
- String s= (String) o;
- //吐司Android studio与web后台数据交互获得的值
- Toast.makeText(MainActivity.this, s, Toast.LENGTH_SHORT).show();
- }
- }
-
- }
Main2Activity:
- package com.example.android_getandpost;
-
- 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 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 Main2Activity extends AppCompatActivity {
-
- private EditText upass;
- private EditText uname;
-
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.activity_main2);
-
- uname = (EditText) findViewById(R.id.uname);
-
- upass = (EditText) findViewById(R.id.upass);
- }
-
- public void LoginPost(View view){
-
- String name=uname.getText().toString();
-
- String pass=upass.getText().toString();
-
- String path="http://193.168.3.16:8080/Login/login.do";
-
- new postTask().execute(name,pass,path);
- }
-
- class postTask extends AsyncTask{
-
- @Override
- protected Object doInBackground(Object[] params) {
-
- String name=params[0].toString();
- String pass=params[1].toString();
- String path=params[2].toString();
- try {
-
- URL url=new URL(path);
-
- HttpURLConnection conn= (HttpURLConnection) url.openConnection();
-
- conn.setRequestMethod("POST");
-
- conn.setConnectTimeout(5000);
-
- String s="uname="+name+"&upass"+pass;
-
- conn.setRequestProperty("Content-Length",s.length()+"");
- conn.setRequestProperty("Content-Type","application/x-www-form-urlencoded");
-
- conn.setDoOutput(true);
-
- OutputStream os=conn.getOutputStream();
- os.write(s.getBytes());
- if(conn.getResponseCode()==200){
-
- InputStream is=conn.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 s= (String) o;
-
- Toast.makeText(Main2Activity.this, s, Toast.LENGTH_SHORT).show();
- }
- }
- }
第三:运用第三方(android-async-http-1.4.4.jar):
首先,在项目中把jar包导入libs,然后右击选择add as library解压,再在build.gradle中的
compileSdkVersion 25
buildToolsVersion "25.0.2"上面加上这样一句代码:useLibrary 'org.apache.http.legacy',然后编译
以解决HttpClient导致不可以问题
activity_mian3.xml:
- <?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"
- tools:context="com.example.android_getandpost.Main3Activity">
-
-
-
- <EditText
- android:layout_width="match_parent"
- android:layout_height="wrap_content"
- android:hint="请输入用户名"
- android:id="@+id/uname"
- />
-
- <EditText
- android:layout_width="match_parent"
- android:layout_height="wrap_content"
- android:hint="请输入密码"
- android:id="@+id/upass"
- />
-
- <Button
- android:layout_width="match_parent"
- android:layout_height="wrap_content"
- android:text="登陆(AsyncHttpClient)"
- android:onClick="LoginAsyncHttpClient"
- />
-
- </LinearLayout>
- <pre code_snippet_id="2504298" snippet_file_name="blog_20170728_10_9188218" class="java" name="code">package com.example.android_getandpost;
-
- 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.RequestHandle;
- import com.loopj.android.http.RequestParams;
- import com.loopj.android.http.TextHttpResponseHandler;
-
- import org.apache.http.Header;
-
- public class Main3Activity extends AppCompatActivity {
-
- private EditText upass;
- private EditText uname;
-
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.activity_main3);
- //获取用户名的id
- uname = (EditText) findViewById(R.id.uname);
- //获取密码的id
- upass = (EditText) findViewById(R.id.upass);
- }
-
- public void LoginAsyncHttpClient(View view){
- //获取用户名的值
- String name=uname.getText().toString();
- //获取密码的值
- String pass=upass.getText().toString();
- //获取网络上的servlet路径
- String path="http://193.168.3.16:8080/Login/login.do";
- //使用第三方
- AsyncHttpClient ahc=new AsyncHttpClient();
- //请求参数
- RequestParams params=new RequestParams();
- //给请求参数设键和值(键的名字和web后台保持一致)
- params.put("name",name);
- params.put("pass",pass);
- //设值提交方式
- ahc.post(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);
- //吐司Android studio与web后台数据交互获得的值
- Toast.makeText(Main3Activity.this, responseBody, Toast.LENGTH_SHORT).show();
- }
- });
- // @Override
- // public void onSuccess(int statusCode, Header[] headers, String responseBody) {
- // super.onSuccess(statusCode, headers, responseBody);
- // Toast.makeText(MainActivity.this, responseBody, Toast.LENGTH_SHORT).show();
- // }
- // });
- }
- }
- </pre><br>
- <pre></pre>
- <pre code_snippet_id="2504298" snippet_file_name="blog_20170728_12_7204133" class="html" style="background-color:#ffffff;color:#000000;font-family:'宋体';font-size:13.5pt;" name="code"></pre><pre code_snippet_id="2504298" snippet_file_name="blog_20170728_12_7204133" class="html" style="background-color:#ffffff;color:#000000;font-family:'宋体';font-size:13.5pt;" name="code"></pre><pre code_snippet_id="2504298" snippet_file_name="blog_20170728_13_9854092" class="html" style="background-color:#ffffff;color:#000000;font-family:'宋体';font-size:13.5pt;" name="code">我在运行的时候总是吐司不出东西,原因是因为我没有连局网
- </pre>
- <p></p>
- <div><br>
- </div>
- <div><strong><span style="font-family:宋体; color:rgb(0,128,0); background-color:rgb(255,255,255)"><br>
- </span></strong></div>
- <span style="color:#008000"><strong></strong></span>
- <div><br>
- </div>
- <pre style="background-color:#ffffff; color:#000000; font-family:'宋体'; font-size:13.5pt"></pre>
- <p><br>
- </p>