下面的示例中对请求进行验证，并添加自定义的错误信息处理。
1. 创建 rest api 和模型类
EmployeeRESTController.java
import javax.validation.Valid;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class EmployeeRESTController {
@PostMapping(value = "/employees")
public ResponseEntity<EmployeeVO> addEmployee (@Valid @RequestBody EmployeeVO employee)
{
return new ResponseEntity<EmployeeVO>(employee, HttpStatus.OK);
}
@GetMapping(value = "/employees/{id}")
public ResponseEntity<EmployeeVO> getEmployeeById (@PathVariable("id") int id)
{
EmployeeVO employee = null;
if(employee == null) {
throw new RecordNotFoundException("Invalid employee id : " + id);
}
return new ResponseEntity<EmployeeVO>(employee, HttpStatus.OK);
}
}
EmployeeVO.java
import java.io.Serializable;
import javax.validation.constraints.Email;
import javax.validation.constraints.NotEmpty;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlRootElement;
@XmlRootElement(name = "employee")
@XmlAccessorType(XmlAccessType.FIELD)
public class EmployeeVO implements Serializable
{
private Integer employeeId;
private String firstName;
private String lastName;
private String email;
public EmployeeVO(Integer id, String firstName, String lastName, String email) {
super();
this.employeeId = id;
this.firstName = firstName;
this.lastName = lastName;
this.email = email;
}
public EmployeeVO() {
}
//Removed setter/getter for readability
}
2. Spring boot 异常处理 - rest 请求验证
2.1 spring 默认验证支持
修改模型类，添加验证。
EmployeeVO.java
package com.example.demoasync.valid;
import java.io.Serializable;
import javax.validation.constraints.Email;
import javax.validation.constraints.NotEmpty;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlRootElement;
@XmlRootElement(name = "employee")
@XmlAccessorType(XmlAccessType.FIELD)
public class EmployeeVO implements Serializable
{
private static final long serialVersionUID = 1L;
public EmployeeVO(Integer id, String firstName, String lastName, String email) {
super();
this.employeeId = id;
this.firstName = firstName;
this.lastName = lastName;
this.email = email;
}
public EmployeeVO() {
}
private Integer employeeId;
@NotEmpty(message = "first name must not be empty")
private String firstName;
@NotEmpty(message = "last name must not be empty")
private String lastName;
@NotEmpty(message = "email must not be empty")
@Email(message = "email should be a valid email")
private String email;
//Removed setter/getter for readability
}
通过 @Valid 注解开启验证：
@PostMapping(value = "/employees")
public ResponseEntity<EmployeeVO> addEmployee (@Valid @RequestBody EmployeeVO employee)
{
EmployeeDB.addEmployee(employee);
return new ResponseEntity<EmployeeVO>(employee, HttpStatus.OK);
}
2.2 异常模型类
RecordNotFoundException.java
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.ResponseStatus;
@ResponseStatus(HttpStatus.NOT_FOUND)
public class RecordNotFoundException extends RuntimeException
{
public RecordNotFoundException(String exception) {
super(exception);
}
}
ErrorResponse.java
import java.util.List;
import javax.xml.bind.annotation.XmlRootElement;
@XmlRootElement(name = "error")
public class ErrorResponse
{
public ErrorResponse(String message, List<String> details) {
super();
this.message = message;
this.details = details;
}
//General error message about nature of error
private String message;
//Specific errors in API request processing
private List<String> details;
//Getter and setters
}
2.3 自定义 ExceptionHandler
CustomExceptionHandler.java
import java.util.ArrayList;
import java.util.List;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.validation.ObjectError;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.context.request.WebRequest;
import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;
@SuppressWarnings({"unchecked","rawtypes"})
@ControllerAdvice
public class CustomExceptionHandler extends ResponseEntityExceptionHandler
{
@ExceptionHandler(Exception.class)
public final ResponseEntity<Object> handleAllExceptions(Exception ex, WebRequest request) {
List<String> details = new ArrayList<>();
details.add(ex.getLocalizedMessage());
ErrorResponse error = new ErrorResponse("Server Error", details);
return new ResponseEntity(error, HttpStatus.INTERNAL_SERVER_ERROR);
}
@ExceptionHandler(RecordNotFoundException.class)
public final ResponseEntity<Object> handleUserNotFoundException(RecordNotFoundException ex, WebRequest request) {
List<String> details = new ArrayList<>();
details.add(ex.getLocalizedMessage());
ErrorResponse error = new ErrorResponse("Record Not Found", details);
return new ResponseEntity(error, HttpStatus.NOT_FOUND);
}
@Override
protected ResponseEntity<Object> handleMethodArgumentNotValid(MethodArgumentNotValidException ex, HttpHeaders headers, HttpStatus status, WebRequest request) {
List<String> details = new ArrayList<>();
for(ObjectError error : ex.getBindingResult().getAllErrors()) {
details.add(error.getDefaultMessage());
}
ErrorResponse error = new ErrorResponse("Validation Failed", details);
return new ResponseEntity(error, HttpStatus.BAD_REQUEST);
}
}
3. 测试
1）HTTP GET /employees/23
HTTP Status : 404
{
"message": "Record Not Found",
"details": [
"Invalid employee id : 23"
]
}
2）HTTP POST /employees
请求：
{
"lastName": "Bill",
"email": "ibill@gmail.com"
}
响应：
HTTP Status : 400
{
"message": "Validation Failed",
"details": [
"first name must not be empty"
]
}
3）HTTP POST /employees
请求：
{
"firstName":"Lokesh",
"email": "ibill_gmail.com" //invalid email in request
}
响应：
HTTP Status : 400
{
"message": "Validation Failed",
"details": [
"last name must not be empty",
"email should be a valid email"
]
}
