简介
本文介绍使用Spring自带的Jackson转换XML与Java对象的方法。
XML与Java对象转换的方法有很多，最好的方法是使用Spring自带的XmlMapper，本文介绍此工具的用法。
XmlMapper类是 ObjectMapper类的子类，两者使用方式几乎一致。
依赖
<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依赖了jackson-core、jackson-databind、jackson-annotations等，这些都在spring-boot-starter-web中引入了。
整个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>
工具类
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()
// // 忽略实体类没有对应属性。如果为 true 会抛出异常
// .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES,false)
// // 忽略null
// .serializationInclusion(JsonInclude.Include.NON_NULL)
// // 属性使用 驼峰首字母小写
// .propertyNamingStrategy(PropertyNamingStrategy.LOWER_CAMEL_CASE)
// .defaultUseWrapper(false)
.build();
// 序列化时加上文件头信息
xmlMapper.configure(ToXmlGenerator.Feature.WRITE_XML_DECLARATION, true);
// 美化输出结果（给XML添加缩进）
xmlMapper.enable(SerializationFeature.INDENT_OUTPUT);
// 把“忽略重复的模块注册”禁用，否则下面的注册不生效
xmlMapper.disable(MapperFeature.IGNORE_DUPLICATE_MODULE_REGISTRATIONS);
xmlMapper.registerModule(configTimeModule());
// 重新设置为生效，避免被其他地方覆盖
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;
}
}
测试类
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 = "测试XML")
@RestController
@RequestMapping("xml")
public class TestController {
@ApiOperation("对象转XML")
@PostMapping("toXmlString")
public String toXmlString() {
SchoolBO schoolBO = new SchoolBO();
schoolBO.setSchoolId(222);
schoolBO.setSchoolName("ABC中学");
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转对象")
@PostMapping("toObject")
public Object toObject(String xml) {
return XmlUtil.toObject(xml, SchoolBO.class);
}
}
实体类
- @JacksonXmlRootElement：指定生成xml根标签的名字
- 属性：namespace，localName
- @JacksonXmlProperty：指定包装标签名，或者指定标签内部属性名
- 属性：namespace，localName，isAttribute(default：false)
- @JacksonXmlElementWrapper：可用于List等集合类，用来指定外围标签名
- 属性：namespace，localName，useWrapping (default：true)
- @JacksonXmlText：指定当前这个值，没有xml标签包裹。
- 属性：namespace，localName
顶层实体类
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标签的名字。若不指定，则为字段名
@JacksonXmlProperty(localName = "SchoolName")
private String schoolName;
// isAttribute 设为true时，该字段做为根标签的属性
@JacksonXmlProperty(isAttribute = true)
private Integer schoolId;
private String schoolEmail;
private String schoolAddress;
// 指定外层的XML标签名
@JacksonXmlElementWrapper(localName = "students")
// 指定单个元素的XML标签名
@JacksonXmlProperty(localName = "item")
private List<StudentBO> studentBOList;
}
子层实体类
package com.knife.example.business.bo;
import lombok.Data;
import java.time.LocalDateTime;
@Data
public class StudentBO {
private String studentName;
private LocalDateTime createTime;
}
测试
1.对象转XML
2.XML转对象
使用此XML测试：
<?xml version='1.0' encoding='UTF-8'?>
<school schoolId="222">
<schoolEmail>aa@163.com</schoolEmail>
<schoolAddress>A省B市</schoolAddress>
<SchoolName>ABC中学</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>
结果：
请先 ！