Spring使用Jackson實現(xiàn)轉換XML與Java對象

更新時間：2024年02月29日 16:17:15 作者：IT利刃出鞘

這篇文章主要為大家詳細介紹了Spring如何使用Jackson實現(xiàn)轉換XML與Java對象,文中的示例代碼講解詳細,感興趣的小伙伴可以跟隨小編一起學習一下

簡介

本文介紹使用Spring自帶的Jackson轉換XML與Java對象的方法。

XML與Java對象轉換的方法有很多，最好的方法是使用Spring自帶的XmlMapper，本文介紹此工具的用法。

XmlMapper類是 ObjectMapper類的子類，兩者使用方式幾乎一致。

依賴

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>
 
<dependency>
    <groupId>com.fasterxml.jackson.dataformat</groupId>
    <artifactId>jackson-dataformat-xml</artifactId>
    <!-- 版本由spring-boot-starter-parent指定-->
</dependency>

jackson-dataformat-xml依賴了jackson-core、jackson-databind、jackson-annotations等，這些都在spring-boot-starter-web中引入了。

整個pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.13</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.knife</groupId>
    <artifactId>Demo_XML_SpringBoot</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>Demo_XML_SpringBoot</name>
    <description>Demo project for Spring Boot</description>
 
    <properties>
        <java.version>1.8</java.version>
    </properties>
 
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
 
        <dependency>
            <groupId>com.fasterxml.jackson.dataformat</groupId>
            <artifactId>jackson-dataformat-xml</artifactId>
        </dependency>
 
        <dependency>
            <groupId>com.github.xiaoymin</groupId>
            <artifactId>knife4j-spring-boot-starter</artifactId>
            <version>3.0.3</version>
        </dependency>
 
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.24</version>
            <scope>provided</scope>
        </dependency>
 
    </dependencies>
 
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
 
</project>

工具類

package com.knife.example.common.util;
 
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.MapperFeature;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.databind.deser.std.DateDeserializers;
import com.fasterxml.jackson.databind.ser.std.DateSerializer;
import com.fasterxml.jackson.dataformat.xml.XmlMapper;
import com.fasterxml.jackson.dataformat.xml.ser.ToXmlGenerator;
import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateDeserializer;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateTimeDeserializer;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalTimeDeserializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateSerializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateTimeSerializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalTimeSerializer;
import lombok.SneakyThrows;
 
import java.text.SimpleDateFormat;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.format.DateTimeFormatter;
import java.util.Date;
 
public class XmlUtil {
    private static final XmlMapper xmlMapper = createXmlMapper();
 
    private static XmlMapper createXmlMapper() {
        XmlMapper xmlMapper = XmlMapper.builder()
                // // 忽略實體類沒有對應屬性。如果為 true 會拋出異常
                // .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES,false)
                // // 忽略null
                // .serializationInclusion(JsonInclude.Include.NON_NULL)
                // // 屬性使用 駝峰首字母小寫
                // .propertyNamingStrategy(PropertyNamingStrategy.LOWER_CAMEL_CASE)
                // .defaultUseWrapper(false)
                .build();
 
        // 序列化時加上文件頭信息
        xmlMapper.configure(ToXmlGenerator.Feature.WRITE_XML_DECLARATION, true);
        // 美化輸出結果（給XML添加縮進）
        xmlMapper.enable(SerializationFeature.INDENT_OUTPUT);
 
        // 把“忽略重復的模塊注冊”禁用，否則下面的注冊不生效
        xmlMapper.disable(MapperFeature.IGNORE_DUPLICATE_MODULE_REGISTRATIONS);
        xmlMapper.registerModule(configTimeModule());
        // 重新設置為生效，避免被其他地方覆蓋
        xmlMapper.enable(MapperFeature.IGNORE_DUPLICATE_MODULE_REGISTRATIONS);
 
        return xmlMapper;
    }
 
    private static JavaTimeModule configTimeModule() {
        JavaTimeModule javaTimeModule = new JavaTimeModule();
 
        String localDateTimeFormat = "yyyy-MM-dd HH:mm:ss";
        String localDateFormat = "yyyy-MM-dd";
        String localTimeFormat = "HH:mm:ss";
        String dateFormat = "yyyy-MM-dd HH:mm:ss";
 
        // 序列化
        javaTimeModule.addSerializer(
                LocalDateTime.class,
                new LocalDateTimeSerializer(DateTimeFormatter.ofPattern(localDateTimeFormat)));
        javaTimeModule.addSerializer(
                LocalDate.class,
                new LocalDateSerializer(DateTimeFormatter.ofPattern(localDateFormat)));
        javaTimeModule.addSerializer(
                LocalTime.class,
                new LocalTimeSerializer(DateTimeFormatter.ofPattern(localTimeFormat)));
        javaTimeModule.addSerializer(
                Date.class,
                new DateSerializer(false, new SimpleDateFormat(dateFormat)));
 
        // 反序列化
        javaTimeModule.addDeserializer(
                LocalDateTime.class,
                new LocalDateTimeDeserializer(DateTimeFormatter.ofPattern(localDateTimeFormat)));
        javaTimeModule.addDeserializer(
                LocalDate.class,
                new LocalDateDeserializer(DateTimeFormatter.ofPattern(localDateFormat)));
        javaTimeModule.addDeserializer(
                LocalTime.class,
                new LocalTimeDeserializer(DateTimeFormatter.ofPattern(localTimeFormat)));
        javaTimeModule.addDeserializer(Date.class, new DateDeserializers.DateDeserializer(){
            @SneakyThrows
            @Override
            public Date deserialize(JsonParser jsonParser, DeserializationContext dc){
                String text = jsonParser.getText().trim();
                SimpleDateFormat sdf = new SimpleDateFormat(dateFormat);
                return sdf.parse(text);
            }
        });
 
        return javaTimeModule;
    }
 
    public static String toXml(Object o) {
        String xml = null;
        try {
            xml = xmlMapper.writeValueAsString(o);
        } catch (JsonProcessingException e) {
            throw new RuntimeException(e);
        }
        return xml;
    }
 
    public static <T> T toObject(String xml, Class<T> cls) {
        T t = null;
 
        try {
            t = xmlMapper.readValue(xml, cls);
        } catch (JsonProcessingException e) {
            throw new RuntimeException(e);
        }
 
        return t;
    }
}

測試類

package com.knife.example.business.controller;
 
import com.knife.example.business.bo.SchoolBO;
import com.knife.example.business.bo.StudentBO;
import com.knife.example.common.util.XmlUtil;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
 
import java.time.LocalDateTime;
import java.util.ArrayList;
import java.util.List;
 
@Api(tags = "測試XML")
@RestController
@RequestMapping("xml")
public class TestController {
 
    @ApiOperation("對象轉XML")
    @PostMapping("toXmlString")
    public String toXmlString() {
        SchoolBO schoolBO = new SchoolBO();
        schoolBO.setSchoolId(222);
        schoolBO.setSchoolName("ABC中學");
        schoolBO.setSchoolEmail("aa@163.com");
        schoolBO.setSchoolAddress("A省B市");
 
        List<StudentBO> studentBOList = new ArrayList<>();
        StudentBO studentBO1 = new StudentBO();
        studentBO1.setStudentName("Tony");
        studentBO1.setCreateTime(LocalDateTime.now());
 
        StudentBO studentBO2 = new StudentBO();
        studentBO2.setStudentName("Peter");
        studentBO2.setCreateTime(LocalDateTime.now().plusSeconds(2));
 
        studentBOList.add(studentBO1);
        studentBOList.add(studentBO2);
 
        schoolBO.setStudentBOList(studentBOList);
 
        return XmlUtil.toXml(schoolBO);
    }
 
    @ApiOperation("XML轉對象")
    @PostMapping("toObject")
    public Object toObject(String xml) {
        return XmlUtil.toObject(xml, SchoolBO.class);
    }
 
}

實體類

@JacksonXmlRootElement：指定生成xml根標簽的名字

屬性：namespace，localName

@JacksonXmlProperty：指定包裝標簽名，或者指定標簽內(nèi)部屬性名

屬性：namespace，localName，isAttribute(default：false)

@JacksonXmlElementWrapper：可用于List等集合類，用來指定外圍標簽名

屬性：namespace，localName，useWrapping (default：true)

@JacksonXmlText：指定當前這個值，沒有xml標簽包裹。

屬性：namespace，localName

頂層實體類

package com.knife.example.business.bo;
 
import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlElementWrapper;
import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlProperty;
import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlRootElement;
import lombok.Data;
 
import java.util.List;
 
@Data
@JacksonXmlRootElement(localName = "school")
public class SchoolBO {
    // 可以指定XML標簽的名字。若不指定，則為字段名
    @JacksonXmlProperty(localName = "SchoolName")
    private String schoolName;
 
    // isAttribute 設為true時，該字段做為根標簽的屬性
    @JacksonXmlProperty(isAttribute = true)
    private Integer schoolId;
 
    private String schoolEmail;
 
    private String schoolAddress;
 
    // 指定外層的XML標簽名
    @JacksonXmlElementWrapper(localName = "students")
    // 指定單個元素的XML標簽名
    @JacksonXmlProperty(localName = "item")
    private List<StudentBO> studentBOList;
}

子層實體類

package com.knife.example.business.bo;
 
import lombok.Data;
 
import java.time.LocalDateTime;
 
@Data
public class StudentBO {
    private String studentName;
 
    private LocalDateTime createTime;
}

測試

1.對象轉XML

2.XML轉對象

使用此XML測試：

<?xml version='1.0' encoding='UTF-8'?>
<school schoolId="222">
  <schoolEmail>aa@163.com</schoolEmail>
  <schoolAddress>A省B市</schoolAddress>
  <SchoolName>ABC中學</SchoolName>
  <students>
    <item>
      <studentName>Tony</studentName>
      <createTime>2023-03-06 19:46:42</createTime>
    </item>
    <item>
      <studentName>Peter</studentName>
      <createTime>2023-03-06 19:46:44</createTime>
    </item>
  </students>
</school>

結果：