玩转spring boot——AOP与表单验证

前言

AOP在大多数的情况下的应用场景是：日志和验证。至于AOP的理论知识我就不做赘述。而AOP的通知类型有好几种，今天的例子我只选一个有代表意义的“环绕通知”来演示。

一、AOP入门

修改“pom.xml”文件

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.github.carter659</groupId>
    <artifactId>spring07</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.4.2.RELEASE</version>
    </parent>

    <name>spring07</name>
    <url>http://maven.apache.org</url>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <java.version>1.8</java.version>
    </properties>


    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-aop</artifactId>
        </dependency>

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

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

pom.xml

修改入口类文件“App.java”：

package com.github.carter659.spring07;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class App {
    
    public static void main(String[] args) {
        SpringApplication.run(App.class, args);
    }
}

App.java

控制器MainController：

package com.github.carter659.spring07;

import java.util.HashMap;
import java.util.Map;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
public class MainController {

    @GetMapping("/")
    public String index() {
        return "index";
    }
 
    @PostMapping("/save")
    public @ResponseBody Map<String, Object> save() {
        Map<String, Object> map = new HashMap<>();
        map.put("msg", "ok");
        return map;
    }
}

我们拦截控制器中的返回Map的方法。

新建切面类文件“AopAspect.java”：

package com.github.carter659.spring07;

import java.util.HashMap;
import java.util.Map;

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.springframework.stereotype.Component;

@Component
@Aspect
public class AopAspect {

    @Around("execution (java.util.Map com.github.carter659.spring07.MainController.*( .. ) ) ")
    public Object invoke(ProceedingJoinPoint point) {
        Map<String, Object> map = null;
        try {
            Object[] args = point.getArgs();
            Object val = point.proceed(args);
            map = (Map<String, Object>) val;
        } catch (Throwable e) {
            e.printStackTrace();
            map = new HashMap<>();
            map.put("msg", e.toString());
        }
        map.put("aop", "拦截了一个请求");
        return map;
    }
}

如果能拦截到MainController中的方法，则会在Map中put一对键值。

templates模板：

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>玩转spring boot——结合AOP</title>
<script src="//cdn.bootcss.com/angular.js/1.5.6/angular.min.js"></script>
<script type="text/javascript">
    /*<![CDATA[*/
    var app = angular.module('app', []);
    app.controller('MainController', function($rootScope, $scope, $http) {
        //保存
        $scope.save = function() {
            $http({
                url : '/save',
                method : 'POST'
            }).success(function(r) {
                $scope.result = JSON.stringify(r)
            });
        }

    });

    /*]]>*/
</script>
</head>
<body ng-app="app" ng-controller="MainController">
    <h1>玩转spring boot——结合AOP</h1>
    <h4>
        <a href="http://www.cnblogs.com/GoodHelper/">from 刘冬的博客</a>
    </h4>
    <input type="button" value="调用" ng-click="save()" />
    <br />
    <h3>调用结果：</h3>
    <p>{{result}}</p>


    <br />
    <a href="http://www.cnblogs.com/GoodHelper/">点击访问原版博客</a>
</body>
</html>

index.html

运行效果：

点击调用按钮后：

二、表单验证

　　由于有了一节的AOP拦截，那么表单验证就完全可以实现了。但是，spring boot给我们提供了原生的表单验证实例。一些简单的验证，我建议实现spring boot自带的验证，因为它足够简单好用，而复杂的验证可以用AOP来实现。

参考：参考：https://spring.io/guides/gs/validating-form-input/

控制器：

package com.github.carter659.spring07;

import java.util.HashMap;
import java.util.Map;

import javax.validation.Valid;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.ResponseBody;

/**
 * 博客出处：http://www.cnblogs.com/GoodHelper/
 * 
 * @author 刘冬
 *
 */
@Controller
public class MainController {

    @GetMapping("/")
    public String index() {
        return "index";
    }

    @PostMapping("/save")
    public @ResponseBody Map<String, Object> save() {
        Map<String, Object> map = new HashMap<>();
        map.put("msg", "ok");
        return map;
    }

    @PostMapping("/saveOrder")
    public @ResponseBody Map<String, Object> saveOrder(@RequestBody @Valid Order order) {
        Map<String, Object> map = new HashMap<>();
        map.put("msg", "ok");
        map.put("order", order);
        return map;
    }
}

MainController.java

在要验证的方法的参数中增加@Valid注解。

修改Order类：

package com.github.carter659.spring07;

import java.util.Date;

import javax.validation.constraints.Min;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;

/**
 * 博客出处：http://www.cnblogs.com/GoodHelper/
 * 
 * @author 刘冬
 *
 */
public class Order {

    public String id;

    @NotNull
    @Size(min = 10, max = 20)
    public String no;

    @NotNull
    public Date date;

    @Min(100)
    @NotNull
    public Integer quantity;

    /**
     * 省略 get set
     */
}

增加这javax.validation.constraints包下的验证注解。

修改index.html：

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>玩转spring boot——结合AOP与表单验证</title>
<script src="//cdn.bootcss.com/angular.js/1.5.6/angular.min.js"></script>
<script type="text/javascript">
    /*<![CDATA[*/
    var app = angular.module('app', []);
    app.controller('MainController', function($rootScope, $scope, $http) {

        $scope.data = {
            no : 'no.1234567890',
            date : '2017-01-01',
            quantity : 100
        };

        $scope.errors = {
            no : '',
            date : '',
            quantity : ''
        };

        //保存
        $scope.save = function() {
            $http({
                url : '/save',
                method : 'POST'
            }).success(function(r) {
                $scope.result = JSON.stringify(r)
            });
        }
        $scope.saveOrder = function() {
            $http({
                url : '/saveOrder',
                method : 'POST',
                data : $scope.data
            }).success(function(r) {
                $scope.result = JSON.stringify(r)
            }).error(function(e) {
                $scope.result = JSON.stringify(e)
                $scope.errors.no = '';
                $scope.errors.date = '';
                $scope.errors.quantity = '';
                for ( var i in e.errors) {
                    var error = e.errors[i];
                    var field = $scope.errors[error.field];
                    if (field == undefined)
                        continue;
                    $scope.errors[error.field] = error.defaultMessage;
                }
            })
        }
    });

    /*]]>*/
</script>
</head>
<body ng-app="app" ng-controller="MainController">
    <h1>玩转spring boot——结合AOP与表单验证</h1>
    <h4>
        <a href="http://www.cnblogs.com/GoodHelper/">from 刘冬的博客</a>
    </h4>
    <input type="button" value="调用" ng-click="save()" />
    <br />
    <br />
    <input type="button" value="保存订单" ng-click="saveOrder()" />
    <br /> 订单信息：
    <br />
    <table cellspacing="1" style="background-color: #a0c6e5">
        <tr>
            <td>编号：</td>
            <td><input ng-model="data.no" /></td>
            <td><font color="red" ng-show="errors.no">{{errors.no}}</font></td>
        </tr>
        <tr>
            <td>日期：</td>
            <td><input ng-model="data.date" /></td>
            <td><font color="red" ng-show="errors.date">{{errors.date}}</font></td>
        </tr>
        <tr>
            <td>数量：</td>
            <td><input ng-model="data.quantity" /></td>
            <td><font color="red" ng-show="errors.quantity">{{errors.quantity}}</font></td>
        </tr>
    </table>
    <br />
    <h3>调用结果：</h3>
    <p>{{result}}</p>


    <br />
    <a href="http://www.cnblogs.com/GoodHelper/">点击访问原版博客</a>
</body>
</html>