从xml到Java对象的Java jaxb反编组返回null值

Question

您好，我是Jaxb新手，已经花了3个多小时搜索这个NullPointerException和这个解编组的东西，但没有找到适合我的东西。我尝试了inputStream、StringReader和Buffered reader，但当我试图将XML文件解压缩到java对象时，所有这些都导致了空值，下面是一个例外：

@XmlRootElement(name = "supplier")
@XmlAccessorType(XmlAccessType.FIELD)
public class SupplierDto {
@XmlAttribute
private String name;
@XmlAttribute(name = "is-importer")
private Boolean isImporter;

public SupplierDto() {
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public Boolean getImporter() {
    return isImporter;
}

public void setImporter(Boolean importer) {
    isImporter = importer;
}

@XmlRootElement(name = "suppliers")
@XmlAccessorType(XmlAccessType.FIELD)
public class SupplierRootDto {

@XmlElement
private List<SupplierDto> supplierDtos;

public SupplierRootDto() {
}

public List<SupplierDto> getSupplierDtos() {
    return supplierDtos;
}

public void setSupplierDtos(List<SupplierDto> supplierDtos) {
    this.supplierDtos = supplierDtos;
}

JAXBContext context = JAXBContext.newInstance(SupplierRootDto.class);
    Unmarshaller unmarshaller = context.createUnmarshaller();

    String path = "suppliers.xml";
    BufferedReader reader = new BufferedReader(new FileReader(new 
File(path)));

    SupplierRootDto list = (SupplierRootDto) 
unmarshaller.unmarshal(reader);

    for (SupplierDto supplierDto : list.getSupplierDtos()) {

this.supplierRepository.saveAndFlush(this.modelMapper.map(supplierDto, 
Supplier.class));
    }

这是XML文件：

<?xml version="1.0" encoding="utf-8"?>
 <suppliers>
 <supplier name="3M Company" is-importer="true"/>
 <supplier name="Agway Inc." is-importer="false"/>
 <supplier name="Anthem, Inc." is-importer="true"/>
 <supplier name="Airgas, Inc." is-importer="false"/>
 <supplier name="Big Lots, Inc." is-importer="true"/>
 <supplier name="Caterpillar Inc." is-importer="false"/>
 <supplier name="Casey's General Stores Inc." is-importer="true"/>
 <supplier name="Cintas Corp." is-importer="false"/>
 <supplier name="Chubb Corp" is-importer="true"/>
 <supplier name="Cintas Corp." is-importer="false"/>
 <supplier name="CNF Inc." is-importer="true"/>
 <supplier name="CMGI Inc." is-importer="true"/>
 <supplier name="The Clorox Co." is-importer="false"/>
 <supplier name="Danaher Corporation" is-importer="true"/>
 <supplier name="E.I. Du Pont de Nemours and Company" is- 
 importer="false"/>
 <supplier name="E*Trade Group, Inc." is-importer="true"/>
 <supplier name="Emcor Group Inc." is-importer="true"/>
 <supplier name="GenCorp Inc." is-importer="false"/>
 <supplier name="IDT Corporation" is-importer="true"/>
 <supplier name="Level 3 Communications Inc." is-importer="false"/>
 <supplier name="Merck &amp; Co., Inc." is-importer="true"/>
 <supplier name="Nicor Inc" is-importer="false"/>
 <supplier name="Olin Corp." is-importer="true"/>
 <supplier name="Paychex Inc" is-importer="true"/>
 <supplier name="Saks Inc" is-importer="false"/>
 <supplier name="Sunoco Inc." is-importer="true"/>
 <supplier name="Textron Inc" is-importer="true"/>
 <supplier name="VF Corporation" is-importer="false"/>
 <supplier name="Wyeth" is-importer="true"/>
 <supplier name="Zale" is-importer="false"/>
</suppliers>

Answer 1

问题是POJOS+注释不能正确映射到提供的XML。具体地说，在“SupplierRootDto”字段中，“SupplierDtos”需要更改或使用注释来重写如下：

@XmlRootElement(name = "suppliers")
@XmlAccessorType(XmlAccessType.FIELD)
public class SupplierRootDto {

    // ADD NAME TO MATCH THE XML ELEMENT
    @XmlElement(name = "supplier")
    private List<SupplierDto> supplierDtos;

    public SupplierRootDto() {
    }

    public List<SupplierDto> getSupplierDtos() {
        return supplierDtos;
    }

    public void setSupplierDtos(List<SupplierDto> supplierDtos) {
        this.supplierDtos = supplierDtos;
    }
}

然后它将正确地解封。