jwt service

build.gradle

@@ -29,6 +29,7 @@ dependencies {
 	compile('org.springframework.boot:spring-boot-starter-hateoas')
 	compile('org.mybatis.spring.boot:mybatis-spring-boot-starter:1.3.0')
 	compile('org.springframework.boot:spring-boot-starter-web')
+	compile('io.jsonwebtoken:jjwt:0.7.0')
 	compileOnly('org.projectlombok:lombok')
 	runtime('com.h2database:h2')
     testCompile 'io.rest-assured:rest-assured:3.0.2'

src/main/java/io/spring/application/JwtService.java

@@ -2,6 +2,10 @@ package io.spring.application;
 
 import io.spring.application.user.UserData;
 
+import java.util.Optional;
+
 public interface JwtService {
     String toToken(UserData userData);
+
+    Optional<String> getSubFromToken(String token);
 }

src/main/java/io/spring/infrastructure/service/DefaultJwtService.java

@@ -0,0 +1,49 @@
+package io.spring.infrastructure.service;
+
+import io.jsonwebtoken.Claims;
+import io.jsonwebtoken.Jws;
+import io.jsonwebtoken.Jwts;
+import io.jsonwebtoken.SignatureAlgorithm;
+import io.jsonwebtoken.SignatureException;
+import io.spring.application.JwtService;
+import io.spring.application.user.UserData;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Service;
+
+import java.util.Date;
+import java.util.Optional;
+
+@Service
+public class DefaultJwtService implements JwtService {
+    private String secret;
+    private int sessionTime;
+
+    public DefaultJwtService(@Value("${jwt.secret}") String secret,
+                             @Value("${jwt.sessionTime}") int sessionTime) {
+        this.secret = secret;
+        this.sessionTime = sessionTime;
+    }
+
+    @Override
+    public String toToken(UserData userData) {
+        return Jwts.builder()
+            .setSubject(userData.getUsername())
+            .setExpiration(expireTimeFromNow())
+            .signWith(SignatureAlgorithm.HS512, secret)
+            .compact();
+    }
+
+    @Override
+    public Optional<String> getSubFromToken(String token) {
+        try {
+            Jws<Claims> claimsJws = Jwts.parser().setSigningKey(secret).parseClaimsJws(token);
+            return Optional.ofNullable(claimsJws.getBody().getSubject());
+        } catch (Exception e) {
+            return Optional.empty();
+        }
+    }
+
+    private Date expireTimeFromNow() {
+        return new Date(System.currentTimeMillis() + sessionTime * 1000);
+    }
+}

src/test/java/io/spring/infrastructure/service/DefaultJwtServiceTest.java

@@ -0,0 +1,46 @@
+package io.spring.infrastructure.service;
+
+import io.spring.application.JwtService;
+import io.spring.application.user.UserData;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.Optional;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.core.IsNull.notNullValue;
+import static org.junit.Assert.*;
+
+public class DefaultJwtServiceTest {
+
+    private JwtService jwtService;
+
+    @Before
+    public void setUp() throws Exception {
+        jwtService = new DefaultJwtService("123123", 3600);
+    }
+
+    @Test
+    public void should_generate_and_parse_token() throws Exception {
+        String username = "aisensiy";
+
+        UserData userData = new UserData("aisensiy@163.com", username, "", "");
+        String token = jwtService.toToken(userData);
+        assertThat(token, notNullValue());
+        Optional<String> optional = jwtService.getSubFromToken(token);
+        assertThat(optional.isPresent(), is(true));
+        assertThat(optional.get(), is(username));
+    }
+
+    @Test
+    public void should_get_null_with_wrong_jwt() throws Exception {
+        Optional<String> optional = jwtService.getSubFromToken("123");
+        assertThat(optional.isPresent(), is(false));
+    }
+
+    @Test
+    public void should_get_null_with_expired_jwt() throws Exception {
+        String token = "eyJhbGciOiJIUzUxMiJ9.eyJzdWIiOiJhaXNlbnNpeSIsImV4cCI6MTUwMjE2MTIwNH0.SJB-U60WzxLYNomqLo4G3v3LzFxJKuVrIud8D8Lz3-mgpo9pN1i7C8ikU_jQPJGm8HsC1CquGMI-rSuM7j6LDA";
+        assertThat(jwtService.getSubFromToken(token).isPresent(), is(false));
+    }
+}