idea后台与Android数据的交互(IDEA Android sdk)

实现功能向后台发送数据，后台根据获取的数据查询数据库，并将相应的数据发送回客户端，以在界面开发工具中显示。客户端下面是需要创建或修改的文件，新手可以从客户端学习运行示例代码，显示登录用户名输入框和登录密码输入框。

实现功能:Android app向idEA后台发送ID数据，后台根据获取的ID数据查询数据库，并将相应的数据发送回客户端，在app界面显示。

开发工具:IDEA，Android studio，MySQL

Android端:(以下是初学者学习需要创建或修改的文件)Java:主活动来宾服务器布局:activity _ main build . gradle(app)and oid manifest . XML客户端运行示例:代码显示:

导入androidx . app compat . app . app compat activity；导入Android . OS . bundle；导入Android . OS . handler；导入Android . OS . message；导入Android . view . view；导入Android . widget . button；导入Android . widget . edittext；导入Android . widget . textview；导入Android . widget . toast；导入org . JSON . JSON exception；导入org . JSON . JSON object；导入Java . io . buffered reader；导入Java . io . file inputstream；导入Java . io . io exception；导入Java . io . inputstreamreader；公共类主活动扩展app compatibility {//登录用户名输入框私有EditText et _ username//登录密码输入框私有EditText et _ password//登录按钮私有EditText id私有按钮bt _ login私人TextView电视；@ Override protected void onCreate(Bundle savedInstanceState){ super . onCreate(savedInstanceState)；setContentView(r . layout . activity _ main)；//获取组件init()；//点击登录按钮监控Bt _ log in . setonclicklistener(new view . onclick listener(){ @ override public void onclick(view v)){//toast。maketext(登录活动。这个，“登录成功！”，吐司。长度_长)。show()；final Handler my Handler = new Handler(){ public void handle Message(Message msg){ String response result =(String)msg . obj；//吐司。maketext(登录活动。这个，“登录成功！”，吐司。长度_长)。show()；//成功登录系统。out . println(" response "+响应结果)；try { JSON object root = new JSON object(response result)；string userName = root . getstring(" userName ")；TV . append(" userName "+" = "+userName+"/n ")；} catch(JSON exception e){ e . printstacktrace()；} if(响应结果。equals ("+"true ")) {toast。make text(com . example . my application . main activity . this，“登录成功！“，干杯。长度_长)。show()；}//登录失败else {toast。make text(com . example . my application . main activity . this，“登录失败！“，干杯。长度_长)。show()；} } };new Thread(new Runnable(){ @ Override public void run(){ guest toserver guest toserver = new guest toserver()；尝试{//如果您正在调用方法来验证GuestToServer中的用户名和密码，请使用下面的语句//String result = guest toserver . dopost(et _ username . gettext()。toString()。trim()，et_password.getText()。toString()。trim())；string result = guettoserver . dopost(id . gettext()。toString()。trim())；Message msg = new Message()；msg.obj = resultmy handler . sendmessage(msg)；} catch(io exception e){ e . printstacktrace()；} } }).start()；} });}/* * * Get component */private void init(){ et _ username =(edittext)findviewbyid(r . id . et _ username)；et _ password =(EditText)findViewById(r . id . et _ password)；id =(EditText)findViewById(r . id . id)；Bt _ log in =(Button)findViewById(r . id . Bt _ log in)；TV =(TextView)findViewById(r . id . TV)；//获取TextView组件} } Guest to server导入Android . util . log；导入org . Apache . http . http entity；导入org . Apache . http . httpresponse；导入org . Apache . http . http status；import org . Apache . http . name value pair；导入org . Apache . http . client . http client；导入org . Apache . http . client . entity . urlencodedformentity；导入org . Apache . http . client . methods . http post；import org . Apache . http . impl . client . default http client；import org . Apache . http . message . basic name value pair；导入Java . io . buffered reader；导入Java . io . io exception；导入Java . io . inputstream；导入Java . io . inputstreamreader；导入Java . net . httpurl connection；导入Java . net . malformedurexception；导入Java . net . URL；导入Java . util . ArrayList；导入Java . util . list；公有类guest server {//localhost是本地主机的IP地址/login是idea后台项目名称私有字符串URL = " http://localhost:8080/log in "；//服务器返回的结果//String result = " "；/* * *使用Post向服务器发送请求并返回响应* *//如果使用验证用户名和密码的方法，使用公共字符串dopost (string username，String password)throwsioexception { *//并释放以下两个参数设置//* @ Parausername传递给服务器的用户名//* @ Parapassword传递给服务器的密码* @ param id id * @ return */publicstringdopost(stringid)throwsioexception { http client http client = new default http client()；http post http post = new http post(URL)；name value pair param 3 = new basic name value pair(" id "，id)；list params = new ArrayList()；params . add(param 3)；//将参数包装在HttpEntity中，放入HttpPost的请求体中；HttpEntity HttpEntity = New UrlencodedforEntity(params，" GBK ")；http post . setentity(http entity)；HttpResponse HttpResponse = http client . execute(http post)；//如果响应成功，则if (httpresponse。getstatusline()。getstatuscode () = = httpstatus。sc _ ok){//获取消息体httpentity = httpresponse。get entity()；InputStream InputStream = entity . get content()；buffered reader br = new buffered reader(new InputStreamReader(inputStream))；String readLine = nullwhile ((readLine = br.readLine())！= null){ result+= readLine；} inputstream . close()；返回结果；}//响应失败else { return " false} } /*公共字符串doPost(字符串用户名，字符串密码)抛出io exception { http client http client = new default http client()；http post http post = new http post(URL)；//将用户名和密码参数加载到列表中；name value pair param 1 = new basic name value pair("用户名"，用户名)；name value pair param 2 = new basic name value pair(" password "，密码)；list params = new ArrayList()；params . add(param 1)；params . add(param 2)；//将参数包装在HttpEntity中，放入HttpPost的请求体中；HttpEntity HttpEntity = New UrlencodedforEntity(params，" GBK ")；http post . setentity(http entity)；HttpResponse HttpResponse = http client . execute(http post)；//如果响应成功，则if (httpresponse。getstatusline()。getstatuscode () = = httpstatus。sc _ ok){//获取消息体httpentity = httpresponse。get entity()；InputStream InputStream = entity . get content()；buffered reader br = new buffered reader(new InputStreamReader(inputStream))；String readLine = nullwhile ((readLine = br.readLine())！= null){ result+= readLine；} inputstream . close()；返回结果；}//响应失败else { return " false} }*/} activity_main.xml

如果项目中有错误，记得查看错误日志。一般apache不会在build.gradle中导入这一行由于版本不同，有些需要添加在manifest文件的附件中。

至此，Android app已经搭建完成，可以尝试运行IDEA后台项目:可以参考之前的小程序后台，共享一个后台和数据库，不需要改动。