JAXB 解组中的 NULL 值

Question

您好，我想使用 maven 依赖项使用解组来获取嵌套 xml 的值，但最终输出返回空值。我在 maven 项目中使用了 3 个包，并且在获取值后，vehicle.xml 包含 car 的值必须将它们插入到access数据库中

我的 XML 文件---> Vehicle.xml

<?xml version="1.0" encoding="UTF-8"?>

<Vehicle>

   <Car>

      <manufacturer>Maruti</manufacturer>

      <cost>675000</cost>

      <name>Ciaz</name>

      <fueType>Petrol</fueType>

      <driverTye>Manual</driverTye>

   </Car>

   <Car>

      <manufacturer>Maruti</manufacturer>

      <cost>575000</cost>

      <name>Dezire</name>

      <fueType>Petrol</fueType>

      <driverTye>Manual</driverTye>

   </Car>

</Vehicle>

歌唱班

Vehicle.java

package jaxb;

import java.util.List;

import javax.xml.bind.annotation.XmlElement;

import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name="Vehicle")

public class Vehicle {

    @XmlElement

    private List<Car> car;

    public List<Car> getCar() {

        return car;

    }

    /*

     * public Vehicle(List<Car> car) { super(); this.car = car; }

     */

    @Override

    public String toString() {

        return "Vehicle[ Car="+car+"]";

    }

}

Car.java（这是子 POJO）

package jaxb;

import javax.xml.bind.annotation.XmlElement;

import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name="Car")

public class Car {

    private String manufacturer;

    private String name;

    private String driverType;

    private String fuelType;

    private int cost;

    @XmlElement

    public String getManufacturer() {

        return manufacturer;

    }

    public void setManufacturer(String manufacturer) {

        this.manufacturer = manufacturer;

    }

    @XmlElement

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

    @XmlElement

    public String getDriverType() {

        return driverType;

    }

    public void setDriverType(String driverType) {

        this.driverType = driverType;

    }

    @XmlElement

    public String getFuelType() {

        return fuelType;

    }

    public void setFuelType(String fuelType) {

        this.fuelType = fuelType;

    }

Answer 1

Unmarshaller区分大小写。在您的 pojo 中，您有变量名称car，但在 XML 中您有Car. 改成下面的就可以了。<?xml version="1.0" encoding="UTF-8"?><Vehicle>&nbsp; &nbsp;<car>&nbsp; &nbsp; &nbsp; <manufacturer>Maruti</manufacturer>&nbsp; &nbsp; &nbsp; <cost>675000</cost>&nbsp; &nbsp; &nbsp; <name>Ciaz</name>&nbsp; &nbsp; &nbsp; <fueType>Petrol</fueType>&nbsp; &nbsp; &nbsp; <driverTye>Manual</driverTye>&nbsp; &nbsp;</car>&nbsp; &nbsp;<car>&nbsp; &nbsp; &nbsp; <manufacturer>Maruti</manufacturer>&nbsp; &nbsp; &nbsp; <cost>575000</cost>&nbsp; &nbsp; &nbsp; <name>Dezire</name>&nbsp; &nbsp; &nbsp; <fueType>Petrol</fueType>&nbsp; &nbsp; &nbsp; <driverTye>Manual</driverTye>&nbsp; &nbsp;</car></Vehicle>或者您需要明确提及这一点。@XmlElement(name = "Car")private List<Car> car;