关于Token在Android中实现用户登录的使用
原理
在安卓中实现用户登录一般都是用Token，而目前最流行的就是用jwt先讲一下实现的原理：第一步：用户第一次登录，客户端向服务端发送用户和密码，服务端验证用户密码是否正确，如果不正确返回客户端一个消息（用户名错误或者密码错误），如果正确，服务端生成一个Token，并且缓存起来（可以用Redis或者存放数据库）。第二步：客户端接收服务端发送的Token和登陆成功的标识，并且把Token也保存起来，并跳转到登录成功后的页面。第三步：登陆成功后有其他向服务端请求数据的请求，一律在请求头部携带客户端保存的Token，服务端验证这些请求携带的Token是否过期或者不对，正常就返回正常的数据，失败就返回验证Token失败的信息，客服端接收失败的信息提示用户重新登陆，并跳转到登录页。
流程图
前台
第一步：用户第一次登录，客户端向服务端发送用户和密码，
try{
String loginurl = getString(R.string.url2) + "login";
//自己写的工具类
YyHttpRequestOrGetDataFromNet yyHttpRequestOrGetDataFromNet = new YyHttpRequestOrGetDataFromNet();
//以下采用的是将accountid和credential放到JsonObject对象中，
// 因为后台/login设置的参数是一个user对象
JSONObject jsonParam = new JSONObject();
jsonParam.put("credential", password);
jsonParam.put("accountid", accountid);
// System.out.println("token："+yyHttpRequestOrGetDataFromNet.doPost(loginurl,jsonParam));
//把第一次登录服务器生成的Token存在本地
// json格式化
jsonLoginningInfo = yyHttpRequestOrGetDataFromNet.doPost(loginurl,jsonParam);
Gson gson = new Gson();
jsonRootBean = gson.fromJson(jsonLoginningInfo,new TypeToken<JsonRootBean>(){}.getType());
//token 存储
YySharedPrefUtility.setParam(LoginActivity.this,YySharedPrefUtility.Token,
jsonRootBean.getContent().getToken());
System.out.println("tokrn:"+jsonRootBean.getContent().getToken());
System.out.println("tokrn:"+jsonRootBean.getMsg());
}
catch (Exception e){ e.printStackTrace();}
//密码正确：服务端返回1
if (jsonRootBean.getStatus()==0&&jsonRootBean.getMsg().equals("loginSuccess")) {
Toast.makeText(this, "登陆成功", Toast.LENGTH_SHORT).show();
YySharedPrefUtility.setParam(LoginActivity.this,
YySharedPrefUtility.ACCOUNTID, accountid);//用户名存起来
startActivity(new Intent(getApplicationContext(), MainActivity.class));//登录成功跳转首页
}
//用户名不存在或密码错误：服务端返回-1
else {
Toast.makeText(this, "用户名不存在或密码不正确", Toast.LENGTH_SHORT).show();
}这是我改动的工具类
post请求：
public String doPost(String url, JSONObject jsonParam) throws Exception {
/* Translate parameter map to parameter date string */
System.out.println("POST parameter : " + jsonParam.toString());
//以下两行代码非常有用，是网络连接一个严格的格式
//原文博客见
StrictMode.ThreadPolicy policy=new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
//创建URL连接
URL localURL = new URL(url);
URLConnection connection = this.openConnection(localURL);
HttpURLConnection httpURLConnection = (HttpURLConnection) connection;
httpURLConnection.setDoOutput(true);
httpURLConnection.setRequestMethod("POST");//请求方法为Post
httpURLConnection.setRequestProperty("Accept-Charset", charset);
httpURLConnection.setRequestProperty("Content-Type", "application/json");
httpURLConnection.setUseCaches(false);//post不能设置缓存
OutputStream outputStream = null;
OutputStreamWriter outputStreamWriter = null;
InputStream inputStream = null;
InputStreamReader inputStreamReader = null;
BufferedReader reader = null;
StringBuffer resultBuffer = new StringBuffer();
String tempLine = null;
try {
outputStream = httpURLConnection.getOutputStream();
outputStreamWriter = new OutputStreamWriter(outputStream);
//这个地方最关键，将登录传过来的账户和密码
outputStreamWriter.write(jsonParam.toString());
outputStreamWriter.flush();
//判断请求是否成功
if (httpURLConnection.getResponseCode() >= 300) {
throw new Exception("HTTP Request is not success, Response code is " + httpURLConnection.getResponseCode());
}
//接收响应流
inputStream = httpURLConnection.getInputStream();
inputStreamReader = new InputStreamReader(inputStream);
reader = new BufferedReader(inputStreamReader);
while ((tempLine = reader.readLine()) != null) {
resultBuffer.append(tempLine);
}
} finally {
if (outputStreamWriter != null) {
outputStreamWriter.close();
}
if (outputStream != null) {
outputStream.close();
}
if (reader != null) {
reader.close();
}
if (inputStreamReader != null) {
inputStreamReader.close();
}
if (inputStream != null) {
inputStream.close();
}
}
return resultBuffer.toString();//返回数据
}get请求：
//获取JSON数据流数据
public static String doGetJsonStringFromThread(final String u,final String token) {
Thread newThread;
newThread = new Thread(new Runnable() {
@Override
public void run() {
//创建url对象
URL url = null;
try {
//实例化url
url = new URL(u);
//获取HttpURLConnection
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
//设置get请求
connection.setRequestMethod("GET");
//设置超时时间
connection.setConnectTimeout(5 * 1000);
//设置编码
connection.setRequestProperty("contentType", "utf-8");
//注意，最重要的地方，通过setRequestProperty把Token放到请求头
connection.setRequestProperty("token",token);
//连接
connection.connect();
//获取连接响应码
int code = connection.getResponseCode();
//响应失败
if (code >= 300) {
throw new Exception("HTTP Request is not success, Response code is " + code);
}
//如果连接上
if (code == 200) {
// h.sendEmptyMessage(2);
//获取数据
InputStream inputStream = connection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
String line;
StringBuffer buffer = new StringBuffer();
while ((line = bufferedReader.readLine()) != null) {
buffer.append(line);
}
//获取json
jsonBuffer = buffer.toString();
//关闭is
inputStream.close();
}
//关闭连接
connection.disconnect();
} catch (Exception e) {
e.printStackTrace();
}
}
});
newThread.start(); //启动线程
try {
//join方法：让主线程等待子线程运行结束后再继续运行
newThread.join();
} catch (InterruptedException e) {
e.printStackTrace();
}
return jsonBuffer;
}后台
1.拦截器:客户端每像服务端发送请求都要在这里接受一下验证，如果Token失效或者是伪造的Token都会验证出来返回客户端错误的信息
public class JWTInterceptor implements HandlerInterceptor{
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws IOException{
// TODO Auto-generated method stub
String token = request.getHeader("token");
try{
JWTUtils.verify(token);
return true;
}catch (Exception e){
JsonRootBean sJsonBaseObject=new JsonRootBean();
sJsonBaseObject.setMsg("令牌验证失败");
sJsonBaseObject.setStatus(-1);
ObjectMapper objectMapper = new ObjectMapper();
String result = objectMapper.writerWithDefaultPrettyPrinter().writeValueAsString(sJsonBaseObject);
response.setContentType("application/json;charset=UTF-8");
response.getWriter().println(result);
return false;
}
}
}2.jwt工具类
public class JWTUtils {
token密钥(自定义),最好在网上在线生成一个随机字符串，我这里是瞎打的
//这个密钥一定不能泄露
private static final String SING = "!@#$%%^&&*####%%%$%";
//生成Token
public static String getToken(Map<String,String> map){
Calendar instance = Calendar.getInstance();
instance.add(Calendar.HOUR,5);
JWTCreator.Builder builder = JWT.create();
map.forEach((k,v)->{
builder.withClaim(k,v);
});
String token = builder.withExpiresAt(instance.getTime())
.sign(Algorithm.HMAC256(SING));
return token;
}
//根据密钥生成JWT效验器
public static void verify(String token){//解析Token
JWT.require(Algorithm.HMAC256(SING)).build().verify(token);
}
//效验TOKEN
public static DecodedJWT getTokenInfo(String token){
return JWT.require(Algorithm.HMAC256(SING)).build().verify(token);
}
}3.spring.mvc 写在标签的最外面,因为客户端要通过/login来获取Token，所以不能被拦截
<!-- 配置拦截器,验证Token -->
<mvc:interceptors>
<mvc:interceptor>
<!-- 拦截所有/目录下面的页面 -->
<mvc:mapping path="/**"/>
<!-- mvc:exclude-mapping是另外一种拦截，它可以在你后来的测试中对某个页面进行不拦截 -->
<mvc:exclude-mapping path="/login" />
<bean class="com.yunyou.DBI.interceptor.JWTInterceptor"></bean>
</mvc:interceptor>
</mvc:interceptors>4.controller层
其他等等服务层，实体类就没必要给出来了，这里给了一个控制层
@Controller
public class UserLoginningInfoController {
@Autowired
private UserLoginningInfoService uService;
@RequestMapping(value="login",method=RequestMethod.POST)
@ResponseBody
public JsonRootBean login(@RequestBody v_U_userLoginning_info user) {
System.out.println("user"+user.getAccountid()+" "+user.getCredential());
JsonRootBean uJsonBaseObject = new JsonRootBean();
v_U_userLoginning_info us = uService.findUserByPassword(
user.getAccountid(), user.getCredential());
if(us==null) {
uJsonBaseObject.setMsg("loginError");
uJsonBaseObject.setStatus(-1);
return uJsonBaseObject;
}
HashMap<String,String> payload = new HashMap<String,String>();
payload.put("accountid", us.getAccountid());
String token = JWTUtils.getToken(payload);
LoginToken loginToken = new LoginToken();
loginToken.setToken(token);
uJsonBaseObject.setContent(loginToken);
uJsonBaseObject.setMsg("loginSuccess");
return uJsonBaseObject;
}最后就可以啦
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