Java后端本地调试实用方法总结大全

# application.yml
logging:
  level:
    root: INFO
    com.example.service: DEBUG
    com.example.mapper: TRACE

// 通过 Actuator 端点
@RestController
public class LogController {
    @Autowired
    private LoggingSystem loggingSystem;
    
    @PostMapping("/log/level")
    public void setLogLevel(@RequestParam String logger, @RequestParam String level) {
        loggingSystem.setLogLevel(logger, LogLevel.valueOf(level));
    }
}

management:
  endpoints:
    web:
      exposure:
        include: health,info,beans,conditions,env,metrics,mappings,loggers

version: '3.8'
services:
  mysql:
    image: mysql:8.0
    ports:
      - "3306:3306"
    environment:
      MYSQL_ROOT_PASSWORD: root
      MYSQL_DATABASE: test
    volumes:
      - ./init.sql:/docker-entrypoint-initdb.d/init.sql
  
  redis:
    image: redis:7-alpine
    ports:
      - "6379:6379"
  
  kafka:
    image: confluentinc/cp-kafka:latest
    ports:
      - "9092:9092"
    environment:
      KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://localhost:9092
  
  nacos:
    image: nacos/nacos-server:v2.2.3
    ports:
      - "8848:8848"
    environment:
      MODE: standalone

// 测试类配置
@SpringBootTest
@TestPropertySource(locations = "classpath:application-test.yml")
public class UserServiceTest {
    // 使用 H2 内存数据库
}

// application-test.yml
spring:
  datasource:
    url: jdbc:h2:mem:testdb
    driver-class-name: org.h2.Driver
  sql:
    init:
      mode: always
      schema-locations: classpath:schema-h2.sql

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-devtools</artifactId>
    <optional>true</optional>
</dependency>

@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
@AutoConfigureMockMvc
class UserControllerTest {
    @Autowired
    private MockMvc mockMvc;
    
    @MockBean
    private UserService userService; // 自动注入 Mock 对象
    
    @Test
    void testGetUser() throws Exception {
        // 打桩
        when(userService.getUser(1L)).thenReturn(new User("test"));
        
        mockMvc.perform(get("/api/users/{id}", 1L))
               .andExpect(status().isOk())
               .andExpect(jsonPath("$.name").value("test"));
        
        verify(userService, times(1)).getUser(1L);
    }
}

@TestConfiguration
public class TestRedisConfig {
    @Bean
    public RedisServer redisServer() {
        return RedisServer.newRedisServer().start(); // 嵌入式 Redis
    }
}

java -agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=*:5005 -jar app.jar

FROM openjdk:17
EXPOSE 5005
CMD ["java", "-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=*:5005", "-jar", "app.jar"]

-Dcom.sun.management.jmxremote
-Dcom.sun.management.jmxremote.port=9999
-Dcom.sun.management.jmxremote.authenticate=false
-Dcom.sun.management.jmxremote.ssl=false

curl -O https://arthas.aliyun.com/arthas-boot.jar
java -jar arthas-boot.jar # 选择 Java 进程

# 查看 Java 进程
jps

# 生成线程 Dump
jstack <pid> > thread.dump

@Service
public class AsyncService {
    @Async
    public CompletableFuture<User> asyncGetUser(Long id) {
        // 断点会命中，但线程名是 task-1/task-2
        return CompletableFuture.completedFuture(userMapper.selectById(id));
    }
}

@BeforeEach
void setUp() {
    mockServer = ClientAndServer.startClientAndServer(1080);
    
    // 配置 Mock 响应
    mockServer.when(
        request()
            .withMethod("POST")
            .withPath("/api/payment")
    ).respond(
        response()
            .withStatusCode(200)
            .withBody("{\"status\":\"success\"}")
    );
}

# 抓取 8080 端口的 HTTP 请求
sudo tcpdump -i any -w capture.pcap port 8080

# 用 Wireshark 打开分析
wireshark capture.pcap

-XX:+HeapDumpOnOutOfMemoryError
-XX:HeapDumpPath=/path/to/dump.hprof
-XX:+PrintGCDetails
-XX:+PrintGCDateStamps
-Xloggc:/path/to/gc.log

logging:
  level:
    com.example.mapper: DEBUG # 打印 SQL 和参数

<dependency>
    <groupId>p6spy</groupId>
    <artifactId>p6spy</artifactId>
</dependency>

# 开启 DEBUG 日志
java -jar app.jar --debug

# 查看自动配置报告
java -jar app.jar --debug > auto-config-report.txt

# 启动时打印 Bean 创建过程
-Dlogging.level.org.springframework.beans.factory=DEBUG