📜  实现RESTful服务的验证

📅  最后修改于: 2021-01-12 00:50:11             🧑  作者: Mango

实施RESTful服务的验证

验证是所有服务中的普遍要求。我们将讨论Java验证API,以在我们的bean文件中添加验证。当我们收到创建用户的请求时,我们应该验证其内容。如果无效,我们应该返回适当的答复。

让我们看看如何验证请求。

步骤1:打开UserResource.java文件。

步骤2:添加@Valid批注。它是一个Javax验证API。它的默认类路径是spring-boot-starter-web。

UserResource.java

package com.javatpoint.server.main.user;
import java.net.URI;
import java.util.List;
import javax.validation.Valid;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.DeleteMapping;
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;
import org.springframework.web.servlet.support.ServletUriComponentsBuilder;
@RestController
public class UserResource 
{
@Autowired
private UserDaoService service;
@GetMapping("/users")
public List retriveAllUsers()
{
return service.findAll();
}
//retrieves a specific user detail
@GetMapping("/users/{id}")
public User retriveUser(@PathVariable int id)
{
User user= service.findOne(id);
if(user==null)
//runtime exception
throw new UserNotFoundException("id: "+ id);
return user;
}
//method that delete a user resource
@DeleteMapping("/users/{id}")
public void deleteUser(@PathVariable int id)
{
User user= service.deleteById(id);
if(user==null)
//runtime exception
throw new UserNotFoundException("id: "+ id);
}
//method that posts a new user detail and returns the status of the user resource
@PostMapping("/users")
public ResponseEntity createUser(@Valid @RequestBody User user)    
{
User sevedUser=service.save(user);    
URI location=ServletUriComponentsBuilder.fromCurrentRequest().path("/{id}").buildAndExpand(sevedUser.getId()).toUri();
return ResponseEntity.created(location).build();
}
}


现在,我们将在User类中添加有关姓名出生日期的验证。假设名称至少应包含五个字符,并且出生日期应该是过去而不是现在。

步骤3:打开User.java文件。

步骤4:name变量上方添加@Size(min = 5)批注。

步骤5:dob变量上方添加@Past批注。

User.java

package com.javatpoint.server.main.user;
import java.util.Date;
import javax.validation.constraints.Past;
import javax.validation.constraints.Size;
public class User 
{
private Integer id;
@Size(min=5)
private String name;
@Past
private Date dob;
//default constructor    
protected User()
{
    
}
public User(Integer id, String name, Date dob) 
{
super();
this.id = id;
this.name = name;
this.dob = dob;
}
public Integer getId() 
{
return id;
}
public void setId(Integer id) 
{
this.id = id;
}
public String getName() 
{
return name;
}
public void setName(String name) 
{
this.name = name;
}
public Date getDob() 
{
return dob;
}
public void setDob(Date dob) 
{
this.dob = dob;
}
@Override
public String toString() 
{
//return "User [id=" + id + ", name=" + name + ", dob=" + dob + "]";
return String.format("User [id=%s, name=%s, dob=%s]", id, name, dob);
}
}

步骤5:打开Rest客户端Postman并发送带有新用户名Tony k的POST请求。它返回状态:201已创建

现在,我们发送另一个POST请求。但是名称应少于五个字符。它返回状态:400 Bad Request

创建RESTful服务时,我们需要考虑消费者,消费者如何知道出了什么问题。若要解决此问题,我们将添加一个方法handleMethodArgumentNotValid(),该方法在ResponseEntityExceptionHandler类中定义。这是发生错误请求时触发的方法。

protected ResponseEntity handleMethodArgumentNotValid(  MethodArgumentNotValidException ex, HttpHeaders headers, HttpStatus status, WebRequest request) 
{
return handleExceptionInternal(ex, null, headers, status, request);
}


步骤6:将上述方法复制并粘贴到CustomizedResponseEntityExceptionHandler.java文件中。

步骤7:通过添加注释@Override来覆盖方法

CustomizedResponseEntityExceptionHandler.java

package com.javatpoint.server.main;
import java.util.Date;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.context.request.WebRequest;
import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;
import com.javatpoint.server.main.exception.ExceptionResponse;
import com.javatpoint.server.main.user.UserNotFoundException;
//defining exception handling for all the exceptions 
@ControllerAdvice
@RestController
public class CustomizedResponseEntityExceptionHandler extends ResponseEntityExceptionHandler
{
@ExceptionHandler(Exception.class)
//override method of ResponseEntityExceptionHandler class
public final ResponseEntity handleAllExceptions(Exception ex, WebRequest request)
{
//creating exception response structure
ExceptionResponse exceptionResponse= new ExceptionResponse(new Date(), ex.getMessage(), request.getDescription(false));
//returning exception structure and specific status 
return new ResponseEntity(exceptionResponse, HttpStatus.INTERNAL_SERVER_ERROR);
}
@ExceptionHandler(UserNotFoundException.class)
//override method of ResponseEntityExceptionHandler class
public final ResponseEntity handleUserNotFoundExceptions(UserNotFoundException ex, WebRequest request)
{
//creating exception response structure
ExceptionResponse exceptionResponse= new ExceptionResponse(new Date(), ex.getMessage(), request.getDescription(false));
//returning exception structure and specific status 
return new ResponseEntity(exceptionResponse, HttpStatus.NOT_FOUND);
}
@Override
protected ResponseEntity handleMethodArgumentNotValid(MethodArgumentNotValidException ex, HttpHeaders headers, HttpStatus status, WebRequest request) 
{
ExceptionResponse exceptionResponse= new ExceptionResponse(new Date(), ex.getMessage(), ex.getBindingResult().toString());
//returning exception structure and specific status 
return new ResponseEntity(exceptionResponse, HttpStatus.BAD_REQUEST);
}
}


步骤8:现在,我们通过Postman发送POST请求。它返回异常结构,并显示消息验证参数和其他详细信息失败。

很难为用户理解消息。因此,我们现在将使用字符串验证失败来自定义消息,而不是获取消息。

@Override
protected ResponseEntity handleMethodArgumentNotValid(MethodArgumentNotValidException ex, HttpHeaders headers, HttpStatus status, WebRequest request) 
{
ExceptionResponse exceptionResponse= new ExceptionResponse(new Date(), "Validation Failed", ex.getBindingResult().toString());
//returning exception structure and specific status 
return new ResponseEntity(exceptionResponse, HttpStatus.BAD_REQUEST);
}


步骤9:再次发送POST请求。它返回我们已定制的消息。

这可能对消费者有用。现在,我们再次自定义消息,并使其更加针对错误。

步骤10:打开User.java文件,并在@Size批注中添加属性message =“名称应至少包含5个字符”

@Size(min=5, message="Name should have at least 5 characters")

步骤11:再次发送POST请求。它返回我们指定的更具体的异常。

通过遵循BindingResult接口,我们可以进一步自定义异常。有各种各样的异常消息。在validation-api-2.0.1.Final.jar中定义了以下验证类。