Java 当字符串值为整数时,没有字符串参数构造函数/工厂方法从字符串值反序列化
我正在尝试将以下xml反序列化到对象中:Java 当字符串值为整数时,没有字符串参数构造函数/工厂方法从字符串值反序列化,java,jackson,xmlmapper,Java,Jackson,Xmlmapper,我正在尝试将以下xml反序列化到对象中: <?xml version="1.0" encoding="iso-8859-1" ?> <foo> <dean> <bar>28</bar> <bar>31</bar> </dean> </foo> } 下面是失败的测试,xmlMapper抛出异常 @Test public void shou
<?xml version="1.0" encoding="iso-8859-1" ?>
<foo>
<dean>
<bar>28</bar>
<bar>31</bar>
</dean>
</foo>
}
下面是失败的测试,xmlMapper抛出异常
@Test
public void shouldParseAndCreateObject() throws Exception {
final JacksonXmlModule jacksonXmlModule = new JacksonXmlModule();
XmlMapper xmlMapper = (XmlMapper) new XmlMapper(jacksonXmlModule)
.disable(FAIL_ON_UNKNOWN_PROPERTIES, FAIL_ON_IGNORED_PROPERTIES);
Foo foo = xmlMapper.readValue("<?xml version=\"1.0\" encoding=\"iso-8859-
1\" ?>\n" +
"<foo>\n" +
" <dean>\n" +
" <bar>28</bar>\n" +
" <bar>31</bar>\n" +
" </dean>\n" +
"</foo>", Foo.class);
assertThat(foo.getDean().getBar().get(0).getValue(), is(28));
}
com.fasterxml.jackson.databind.JsonMappingException: Can not construct instance of Bar: no String-argument constructor/factory method to deserialize from String value ('28')
@测试
public void shouldParseAndCreateObject()引发异常{
最终JacksonXmlModule JacksonXmlModule=新JacksonXmlModule();
XmlMapper XmlMapper=(XmlMapper)新的XmlMapper(jacksonXmlModule)
.禁用(未知属性失败,忽略属性失败);
Foo Foo=xmlMapper.readValue(“\n”+
“\n”+
“\n”+
“28\n”+
“31\n”+
“\n”+
“”,Foo.class);
断言(foo.getDean().getBar().get(0.getValue())为(28));
}
com.fasterxml.jackson.databind.JsonMappingException:无法构造Bar的实例:没有要从字符串值('28'反序列化的字符串参数构造函数/工厂方法
在[Source:out/test/resources/test.xml;第4行,第16列](通过引用链:service.Foo[“dean”]->service.dean[“bar”]->java.util.ArrayList[0])
从读取异常来看,映射程序似乎将值28视为字符串而不是整数,但如果我将Bar类更改为以下内容,并将元素Bar的属性添加到原始xml中,则相同的测试通过
public class Bar {
private String test;
@JacksonXmlText
private Integer value;
public Bar(@JacksonXmlProperty(localName = "test", isAttribute = true) String
test, @JacksonXmlProperty(localName = " ") Integer value) {
this.test = test;
this.value = value;
}
public String getTest() {
return test;
}
public Integer getValue() {
return value;
}
<?xml version="1.0" encoding="iso-8859-1" ?>
<foo>
<dean>
<bar test="haha1">28</bar>
<bar test="haha2">31</bar>
</dean>
</foo>
@Test
public void shouldParseAndCreateObject() throws Exception {
final JacksonXmlModule jacksonXmlModule = new JacksonXmlModule();
XmlMapper xmlMapper = (XmlMapper) new XmlMapper(jacksonXmlModule)
.disable(FAIL_ON_UNKNOWN_PROPERTIES, FAIL_ON_IGNORED_PROPERTIES);
Foo foo = xmlMapper.readValue("<?xml version=\"1.0\" encoding=\"iso-8859-
1\" ?>\n" +
"<foo>\n" +
" <dean>\n" +
" <bar test=\"haha1\">28</bar>\n" +
" <bar test=\"haha2\">31</bar>\n" +
" </dean>\n" +
"</foo>" +
"</foo>", Foo.class);
assertThat(foo.getDean().getBar().get(0).getValue(), is(28));
}
公共类栏{
私有字符串测试;
@JacksonXmlText
私有整数值;
公共条(@JacksonXmlProperty(localName=“test”,isAttribute=true)字符串
测试,@JacksonXmlProperty(localName=”“)整数值){
这个。测试=测试;
这个值=值;
}
公共字符串getTest(){
回归试验;
}
公共整数getValue(){
返回值;
}
28
31
@试验
public void shouldParseAndCreateObject()引发异常{
最终JacksonXmlModule JacksonXmlModule=新JacksonXmlModule();
XmlMapper XmlMapper=(XmlMapper)新的XmlMapper(jacksonXmlModule)
.禁用(未知属性失败,忽略属性失败);
Foo Foo=xmlMapper.readValue(“\n”+
“\n”+
“\n”+
“28\n”+
“31\n”+
“\n”+
"" +
“”,Foo.class);
断言(foo.getDean().getBar().get(0.getValue())为(28));
}
我想说的是,映射程序应该从构造函数参数类型推断类型,并尝试使用字符串值实例化该对象,然后在引擎盖下执行类似Integer.valueOf(“28”)的操作,将其添加到POJO空构造函数中,以及所有字段中。 还可以尝试以下操作:
gradle
ext {
jacksonVersion = "2.8.9"
JacksonXmlModule module = new JacksonXmlModule();
module.setDefaultUseWrapper(false);
XmlMapper xmlMapper = new XmlMapper(module);
如果你从
Bar
构造函数中删除参数,它就可以工作了。但是这意味着你需要使类不可变,这不是你想要的。对不起!
public class Bar {
private String test;
@JacksonXmlText
private Integer value;
public Bar(@JacksonXmlProperty(localName = "test", isAttribute = true) String
test, @JacksonXmlProperty(localName = " ") Integer value) {
this.test = test;
this.value = value;
}
public String getTest() {
return test;
}
public Integer getValue() {
return value;
}
<?xml version="1.0" encoding="iso-8859-1" ?>
<foo>
<dean>
<bar test="haha1">28</bar>
<bar test="haha2">31</bar>
</dean>
</foo>
@Test
public void shouldParseAndCreateObject() throws Exception {
final JacksonXmlModule jacksonXmlModule = new JacksonXmlModule();
XmlMapper xmlMapper = (XmlMapper) new XmlMapper(jacksonXmlModule)
.disable(FAIL_ON_UNKNOWN_PROPERTIES, FAIL_ON_IGNORED_PROPERTIES);
Foo foo = xmlMapper.readValue("<?xml version=\"1.0\" encoding=\"iso-8859-
1\" ?>\n" +
"<foo>\n" +
" <dean>\n" +
" <bar test=\"haha1\">28</bar>\n" +
" <bar test=\"haha2\">31</bar>\n" +
" </dean>\n" +
"</foo>" +
"</foo>", Foo.class);
assertThat(foo.getDean().getBar().get(0).getValue(), is(28));
}
JacksonXmlModule module = new JacksonXmlModule();
module.setDefaultUseWrapper(false);
XmlMapper xmlMapper = new XmlMapper(module);