Spring 4 Spring MVC 4 REST + Jackson @JsonView集成实例详解

青山师

发布于 2023-05-04 20:33:06

7820

发布于 2023-05-04 20:33:06

文章被收录于专栏：IT当时语_青山师_JAVA技术栈IT当时语_青山师_JAVA技术栈

分享一个使用SpringMVC4 Rest 和Jackson的@JsonView注解集成的实例。@JsonView用来过滤JSON响应。Spring4.1开始直接支持@JsonView注解。要使用@JsonView，首先我们需要定义视图，我们可以定义多个视图。一个视图定义可以继承其他视图定义。我们的POJO使用@JsonView注解属性传递已经定义的视图。在Spring的Controller我们可以使用Jackson的@JsonView注解我们的方法。序列化Http响应体的时候，JSON响应将在配置视图的基础上进行过滤。我们也可以在Spring REST Client使用@JsonView注解。Spring提供了MappingJacksonValue 包装POJO和序列化视图设置，在发送到web服务器短的时候，我们可以使用RestTemplate来过滤JSON。现在一步一步呈现完整的示例。

准备条件

Java8以上
Spring 4.2.6.RELEASE
Jackson 2.6.6
Tomcat 8以上
Maven
Eclipse

项目结构视图

Maven的pom.xml文件

pom.xml:

<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>org.byron4j</groupId>
    <artifactId>springMVC4-rest-jackson-jsonview-annotation</artifactId>
    <version>1.0.0-SNAPSHOT</version>
    <packaging>war</packaging>

    <name>springMVC4-rest-jackson-jsonview-annotation</name>
    <url>http://blog.csdn.net/zixiao217/article</url>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <spring.framework.version>4.2.6.RELEASE</spring.framework.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${spring.framework.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.framework.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>${spring.framework.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>${spring.framework.version}</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.6.6</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
        </dependency>

    </dependencies>
    <build>
        <finalName>springMvc4-rest</finalName>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.5.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

创建JSON视图的定义

该对象可以在序列化Http响应时通过@JsonView来过滤。第一步使用@JsonView，我们需要创建JSON视图定义。我们需要创建接口或静态类。对于一个以上的视图，我们可以创建一个以上的接口。最好是创建组合接口。在一个类里面创建多个接口以应对多个序列化Http响应的视图。要继承一个视图，我们可以使用另一个接口来继承。

Profile.java：

package org.byron4j.springMVC4_rest_jackson_jsonview_annotation;

public class Profile {
    public interface PublicView {}
    public interface FriendsView extends PublicView{}
    public interface FamilyView extends FriendsView {}
}

Profile类中，我们正在为用户资料创建一个视图筛选器机制。我们创建了3个资料视图，PublicView、FriendsView 和FamilyView 。FriendsView 继承了PublicView，FamilyView 则继承了FriendsView 。

使用`@JsonView`注解创建POJO

Jackson 提供了com.fasterxml.jackson.annotation.JsonView注解属性，该属性将会在序列化Http响应的时候包含进去。

1.在我们的PublicView中，只有@JsonView(Profile.PublicView.class)注解的属性才会过滤。

2.在FriendsView 中，只有@JsonView(Profile.PublicView.class)和@JsonView(Profile.FriendsView.class)注解的属性才会过滤。

3.在FamilyView 中，@JsonView(Profile.PublicView.class)、@JsonView(Profile.FriendsView.class)和@JsonView(Profile.FamilyView .class)注解的属性均会过滤。

Address.java:

package org.byron4j.springMVC4_rest_jackson_jsonview_annotation.pojo;


import org.byron4j.springMVC4_rest_jackson_jsonview_annotation.Profile;

import com.fasterxml.jackson.annotation.JsonView;

public class Address {
    @JsonView(Profile.FamilyView.class)
    private String houseNo;
    @JsonView(Profile.FriendsView.class)
    private String city;
    @JsonView(Profile.PublicView.class)
    private String country;
    public Address(String houseNo, String city, String country) {
        this.houseNo = houseNo;
        this.city = city;
        this.country = country;
    }
    public String getHouseNo() {
        return houseNo;
    }
    public void setHouseNo(String houseNo) {
        this.houseNo = houseNo;
    }
    public String getCity() {
        return city;
    }
    public void setCity(String city) {
        this.city = city;
    }
    public String getCountry() {
        return country;
    }
    public void setCountry(String country) {
        this.country = country;
    }
}

College.java:

package org.byron4j.springMVC4_rest_jackson_jsonview_annotation.pojo;


import org.byron4j.springMVC4_rest_jackson_jsonview_annotation.Profile;

import com.fasterxml.jackson.annotation.JsonView;

public class College {
    @JsonView(Profile.PublicView.class)
    private String colName;
    @JsonView(Profile.FriendsView.class)
    private String colLocation;
    public College(String colName, String colLocation) {
        this.colName = colName;
        this.colLocation = colLocation;
    }
    public String getColName() {
        return colName;
    }
    public void setColName(String colName) {
        this.colName = colName;
    }
    public String getColLocation() {
        return colLocation;
    }
    public void setColLocation(String colLocation) {
        this.colLocation = colLocation;
    }
}

User.java:

package org.byron4j.springMVC4_rest_jackson_jsonview_annotation.pojo;


import org.byron4j.springMVC4_rest_jackson_jsonview_annotation.Profile;

import com.fasterxml.jackson.annotation.JsonView;

public class User {
    @JsonView(Profile.PublicView.class)     
    private String userId;
    private String password;    
    private int age;            
    @JsonView(Profile.FamilyView.class) 
    private long mobnum;        
    @JsonView(Profile.FriendsView.class)
    private String mailId;
    @JsonView(Profile.PublicView.class) 
    private String name;    
    @JsonView(Profile.PublicView.class)     
    private College college;
    @JsonView(Profile.PublicView.class)     
    private Address address;
    public User(String userId, String password, int age, long mobnum, String mailId, 
            String name, College college, Address address) {
        this.userId = userId;
        this.password = password;
        this.age = age;
        this.mobnum = mobnum;
        this.mailId = mailId;
        this.name = name;
        this.college = college;
        this.address = address;
    }
    public String getUserId() {
        return userId;
    }
    public void setUserId(String userId) {
        this.userId = userId;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public long getMobnum() {
        return mobnum;
    }
    public void setMobnum(long mobnum) {
        this.mobnum = mobnum;
    }
    public String getMailId() {
        return mailId;
    }
    public void setMailId(String mailId) {
        this.mailId = mailId;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public College getCollege() {
        return college;
    }
    public void setCollege(College college) {
        this.college = college;
    }
    public Address getAddress() {
        return address;
    }
    public void setAddress(Address address) {
        this.address = address;
    }
}

Name.java:

package org.byron4j.springMVC4_rest_jackson_jsonview_annotation.pojo;

public class Name {
    private String firstName;
    private String middleName;
    private String lastName;
    public String getFirstName() {
        return firstName;
    }
    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }
    public String getMiddleName() {
        return middleName;
    }
    public void setMiddleName(String middleName) {
        this.middleName = middleName;
    }
    public String getLastName() {
        return lastName;
    }
    public void setLastName(String lastName) {
        this.lastName = lastName;
    }
}

使用@JsonView注解创建SpringMVC Controller

Spring4.1以后直接支持Jackson的@JsonView注解。在序列化Http响应的时候，Controller中使用@RequestMapping注解的方法可以直接使用@JsonView注解来过滤JSON视图。

1.在实例的Controller中，使用@JsonView(Profile.PublicView.class)的方法将只产生PublicView属性的JSON响应。

2.使用@JsonView(Profile.FriendsView.class)的方法将只产生PublicView、 FriendsView属性的JSON响应。

3.使用@JsonView(Profile.FamilyView.class)的方法将会产生PublicView、 FriendsView和FamilyView属性的JSON响应。

4.getCompleteProfileById()方法没有被任何试图注解，则会产生所有属性的JSON响应。

UserController.java：

package org.byron4j.springMVC4_rest_jackson_jsonview_annotation;
import java.util.List;

import org.byron4j.springMVC4_rest_jackson_jsonview_annotation.pojo.Name;
import org.byron4j.springMVC4_rest_jackson_jsonview_annotation.pojo.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import com.fasterxml.jackson.annotation.JsonView;
@RestController
@RequestMapping("/app")
public class UserController {
    @Autowired
    private UserService userService;
    @JsonView(Profile.PublicView.class)
    @RequestMapping(value= "/publicprofile", produces = MediaType.APPLICATION_JSON_VALUE)
    public List<User> getAllPublicProfile() {
        List<User> users = userService.getAllUsers();
        return users;
    }   
    @JsonView(Profile.FriendsView.class)
    @RequestMapping(value= "/friendsprofile", produces = MediaType.APPLICATION_JSON_VALUE)
    public List<User> getAllFriendsProfile() {
        List<User> users = userService.getAllUsers();
        return users;
    }   
    @JsonView(Profile.FamilyView.class)
    @RequestMapping(value= "/familyprofile", produces = MediaType.APPLICATION_JSON_VALUE)
    public List<User> getAllFamilyProfile() {
        List<User> users = userService.getAllUsers();
        return users;
    }       
    @RequestMapping(value= "/completeprofile/{userId}", produces = MediaType.APPLICATION_JSON_VALUE)
    public User getCompleteProfileById(@PathVariable(value = "userId") String userId) {
        User user = userService.getUserById(userId);
        return user;
    }
    @RequestMapping(value="/save", method = RequestMethod.POST)
    public ResponseEntity<String> save(@RequestBody Name name) {
        StringBuffer output = new StringBuffer();
        if (name.getFirstName() != null) {
            output.append(" ").append(name.getFirstName());
        }
        if (name.getMiddleName() != null) {
            output.append(" ").append(name.getMiddleName());
        }
        if (name.getLastName() != null) {
            output.append(" ").append(name.getLastName());
        }       
        return new ResponseEntity<String>(output.toString(), HttpStatus.CREATED);
    } 
}

UserService.java:

package org.byron4j.springMVC4_rest_jackson_jsonview_annotation;

import java.util.ArrayList;
import java.util.List;
import java.util.function.Predicate;

import org.byron4j.springMVC4_rest_jackson_jsonview_annotation.pojo.Address;
import org.byron4j.springMVC4_rest_jackson_jsonview_annotation.pojo.College;
import org.byron4j.springMVC4_rest_jackson_jsonview_annotation.pojo.User;
import org.springframework.stereotype.Service;


@Service
public class UserService {
    public User getUserById(String userId) {
        Predicate<User> userPredicate = u-> u.getUserId().equals(userId);
        User obj = list.stream().filter(userPredicate).findFirst().get();
        return obj;
    }   
    public List<User> getAllUsers() { 
        return list;
    }       
    private List<User> list = new ArrayList<>();
    {
        Address address = new Address("A-32", "Varanasi", "India");
        College college = new College("UP College", "Varanasi");
        User user = new User("mohan", "m123", 20, 988745 ,"mohan@gmail.com", "Mohan", college, address);
        list.add(user);
        address = new Address("C-50", "Allahabad", "India");
        college = new College("Allahabad University", "Allahabad");
        user = new User("krishna", "k123", 25, 988345, "krishna@gmail.com", "Krishna", college, address);
        list.add(user);     
        address = new Address("D-40", "Delhi", "India");
        college = new College("JNU", "Delhi");
        user = new User("mahesh", "mh123", 30, 988765, "mahesh@gmail.com", "Mahesh", college, address);
        list.add(user);     
    }
}

Java配置和应用程序初始化

包扫描的Java配置。 AppConfig.java：

package org.byron4j.springMVC4_rest_jackson_jsonview_annotation.config;  

import java.util.List;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

@Configuration 
@ComponentScan("org.byron4j.springMVC4_rest_jackson_jsonview_annotation") 
@EnableWebMvc   
public class AppConfig extends WebMvcConfigurerAdapter {  
    @Override
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
        Jackson2ObjectMapperBuilder builder = new Jackson2ObjectMapperBuilder();
        builder.indentOutput(true);
        converters.add(new MappingJackson2HttpMessageConverter(builder.build()));
    }   
}

Application的初始化配置。 WebAppInitializer.java：

package org.byron4j.springMVC4_rest_jackson_jsonview_annotation.config;
import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;
public class WebAppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer  {
    @Override
    protected Class<?>[] getRootConfigClasses() {
           return new Class[] { AppConfig.class };
    }
    @Override
    protected Class<?>[] getServletConfigClasses() {
           return null;
    }
    @Override
    protected String[] getServletMappings() {
           return new String[]{"/"};
    } 
}

运行服务程序

测试@JsonView(Profile.PublicView.class)，使用http://localhost:8080/springMvc4-rest/app/publicprofile，得到的JSON响应：

[ {
  "userId" : "mohan",
  "name" : "Mohan",
  "college" : {
    "colName" : "UP College"
  },
  "address" : {
    "country" : "India"
  }
}, {
  "userId" : "krishna",
  "name" : "Krishna",
  "college" : {
    "colName" : "Allahabad University"
  },
  "address" : {
    "country" : "India"
  }
}, {
  "userId" : "mahesh",
  "name" : "Mahesh",
  "college" : {
    "colName" : "JNU"
  },
  "address" : {
    "country" : "India"
  }
} ]

测试@JsonView(Profile.FriendsView.class)，使用http://localhost:8080/springMvc4-rest/app/friendsprofile，得到的JSON响应：

[ {
  "userId" : "mohan",
  "mailId" : "mohan@gmail.com",
  "name" : "Mohan",
  "college" : {
    "colName" : "UP College",
    "colLocation" : "Varanasi"
  },
  "address" : {
    "city" : "Varanasi",
    "country" : "India"
  }
}, {
  "userId" : "krishna",
  "mailId" : "krishna@gmail.com",
  "name" : "Krishna",
  "college" : {
    "colName" : "Allahabad University",
    "colLocation" : "Allahabad"
  },
  "address" : {
    "city" : "Allahabad",
    "country" : "India"
  }
}, {
  "userId" : "mahesh",
  "mailId" : "mahesh@gmail.com",
  "name" : "Mahesh",
  "college" : {
    "colName" : "JNU",
    "colLocation" : "Delhi"
  },
  "address" : {
    "city" : "Delhi",
    "country" : "India"
  }
} ]

测试@JsonView(Profile.FamilyView.class)，使用http://localhost:8080/springMvc4-rest/app/friendsprofile，得到的JSON响应：

[ {
  "userId" : "mohan",
  "mobnum" : 988745,
  "mailId" : "mohan@gmail.com",
  "name" : "Mohan",
  "college" : {
    "colName" : "UP College",
    "colLocation" : "Varanasi"
  },
  "address" : {
    "houseNo" : "A-32",
    "city" : "Varanasi",
    "country" : "India"
  }
}, {
  "userId" : "krishna",
  "mobnum" : 988345,
  "mailId" : "krishna@gmail.com",
  "name" : "Krishna",
  "college" : {
    "colName" : "Allahabad University",
    "colLocation" : "Allahabad"
  },
  "address" : {
    "houseNo" : "C-50",
    "city" : "Allahabad",
    "country" : "India"
  }
}, {
  "userId" : "mahesh",
  "mobnum" : 988765,
  "mailId" : "mahesh@gmail.com",
  "name" : "Mahesh",
  "college" : {
    "colName" : "JNU",
    "colLocation" : "Delhi"
  },
  "address" : {
    "houseNo" : "D-40",
    "city" : "Delhi",
    "country" : "India"
  }
} ]

测试getCompleteProfileById()方法，使用http://localhost:8080/springMvc4-rest/app/friendsprofile，得到的JSON响应：

{
  "userId" : "krishna",
  "password" : "k123",
  "age" : 25,
  "mobnum" : 988345,
  "mailId" : "krishna@gmail.com",
  "name" : "Krishna",
  "college" : {
    "colName" : "Allahabad University",
    "colLocation" : "Allahabad"
  },
  "address" : {
    "houseNo" : "C-50",
    "city" : "Allahabad",
    "country" : "India"
  }
}