java报错信息在页面显示的方法：首先自定义异常类；然后在service层的抛出异常类，controller类继承主异常类；接着定义的主异常类，里面可以写多个自己定义的异常类；最后完成信息类代码。

java报错信息在页面显示的方法：

1、自定义异常类

public class ProdProcessOrderException extends RuntimeException {
private static final long serialVersionUID = 1L;
public ProdProcessOrderException(String message) {
super(message);
}
}

2、service层的代码

@Service
public class GeneralDpPpOrderServiceImpl implements GeneralDpPpOrderService {
public ResponseEntity downLoadExcel(GeneralDpPpOrder generalDpPpOrder) {
//.........
//省略代码
if (pOrderRouting == null) {
//此处抛出异常
throw new ProdProcessOrderException("当前门板流程单没有设置生产工艺.");
}
}
}

service层的抛出异常类

3、controller层的代码

@RestController
@RequestMapping("/api/mes/gene-dp-pp-order")
public class GeneralDpPpOrderController extends ExceptionResponse{ //继承主异常类
@Autowired
private GeneralDpPpOrderService generalDpPpOrderService;
@RequestMapping(value = "/download-excel", method = RequestMethod.PUT, consumes = "application/json;charset=UTF-8", produces = "application/xls")
public ResponseEntity downLoadExcel(@RequestBody GeneralDpPpOrder gdp) {
return generalDpPpOrderService.downLoadExcel(gdp);
}

controller类继承主异常类

4、主异常类代码

public abstract class ExceptionResponse {
@ExceptionHandler(ProdProcessOrderException.class)
@ResponseStatus(value = HttpStatus.INTERNAL_SERVER_ERROR)
public SystemMessage prodProcessOrderException(ProdProcessOrderException e) {
return new SystemMessage(500, e.getMessage());
}
}

定义的主异常类，里面可以写多个自己定义的异常类

5、信息类代码

public class SystemMessage {
private int code;
private String message;
public SystemMessage(int code, String message) {
super();
this.code = code;
this.message = message;
}
public int getCode() {
return code;
}
public void setCode(int code) {
this.code = code;
}
public String getMessage() {
return message;
}
public void setMessage(String message) {
this.message = message;
}

通过以上五步，就可以把后台抛出的异常信息，在前端页面显示了