Parameter validator rear V1.0 (calling a method of checking all the parameters and verify the results obtained, and the reason for including errors)

One: Introduction

In writing the back end, the face of a number of parameters, such as phone numbers, passwords, etc. We often need to write validation logic, when more parameters when we will need to verify the need to write a lot of judgment statement, which resulted in a lot of code redundancy. So I developed a validator parameter, just call verification method to instantiate an object parameter validation for all parameters can be passed in object for verification. Word to complete the verification of all parameters.

Project use case:

Complete the registration of business:

 1 @RestController
 2 @RequestMapping("/cmpas/user")
 3 public class UserController {
 4     @Autowired
 5     private IUserService iUserService;
 6     @Autowired
 7     private ResultData resultData;
 8     @Autowired
 9     private ParameterValidator parameterValidator;
10     @RequestMapping(value = "/register",params = {"PhoneNumber","Password","NickName","RealName","Gender"})
11     public ResultData register(HttpSession httpSession, User user)
12     {
13 is          resultData.setResult (parameterValidator.validate (User));
 14          IF (. ResultData.getResult () the equals (ParameterValidator.SUCESS))
 15          {
 16              // verify successful 
. 17              IF (iUserService.insert (User))
 18 is                  resultData. setResult ( "registered successfully" );
 19              the else 
20                  resultData.setResult ( "registration failed" );
 21          }
 22          // the cause of the error returned 
23          return resultData;
 24-      }
 25 }

 

II: development scenario simulation (registered users)

1: user entity

public class User{
private String Username;
private String Password;

//get、set方法

}

　

2: development of its own parameters validator (Inherited abstract class AbstractParameterValidator, writing own validation method)

ParameterValidator the extends AbstractParameterValidator {class public 
　　// check username method 
　　public String the Username (String STR) 
　　{ 
　　　　String = Back "user name is not valid"; // error 
　　　　String regex = "[0-9a-zA -Z] { 1,12} "; // regular expression 
　　　　return str.matches (regex) SUCCESS:? back; // return 
　　} 
　　// check password method 
　　public String password (String str) 
　　{ 
　　　　String the Back =" password invalid " ; 
　　　　String REGEX = "[0-9a-zA-the Z] {8,20}"; 
　　　　return str.matches (REGEX) SUCCESS:? Back; 
　　} 
}

　　

2: Create a new user entity

= The User new new user the User (); 
// user to assign a user instance 
user.setUsername ( "HumorChen"); 
user.setPassword ( "123456");

　　

Validator exemplary call parameters:

// validator object instantiation parameters 
ParameterValidator parameterValidator new new ParameterValidator = (); 
// call the check method 
String Result = parameterValidator.validate (User);

　　When invoked only need to use

parameterValidator.validate (user); 
all by checking the return value AbstractParameterValidator.SUCCESS 
reason otherwise does not pass

 

Three: Structure

 

 The core method validate (Object ... objects) for all fields of the object passed to the parameters of our own validator class prepared to go in there with the same name method, that is, there is no need to be looking for verification, if required to be check the final results are returned

 1     public String validate(Object... objects) {
 2         StringBuilder stringBuilder = new StringBuilder();
 3         for (Object object : objects)
 4             for (Field field : object.getClass().getDeclaredFields()) {
 5                 field.setAccessible(true);
 6                 Method method = null;
 7                 try {
 8                     method = this.getClass().getDeclaredMethod(field.getName(), String.class);
 9                 } catch (Exception e) { }
10                 if (method != null) {
11                     String result =null;
12                     try{
13                         result=(String) method.invoke(this, field.get(object));
14                         //输出日志
15                         log(field.getName(),field.get(object),result);
16                     }catch (Exception e){}
17                     if (!result.equals(SUCESS)) {
18                         if (stringBuilder.length() > 0 && (!outputAllError))
19                             return stringBuilder.toString();
20                         stringBuilder.append(result);
21                         stringBuilder.append("\n");
22                     }
23                 }
24             }
25         return stringBuilder.length() == 0 ? SUCESS : stringBuilder.toString();
26     }