使用Castor实现对象数据绑定
在项目需要从配置文件中读取一些数据， yaml的作为一种可选的非XML方案已经宣告失败， 同事给我推荐了另外两个XML的解决方案： Castor或者Digester
- Castor是一种将Java对象和XML自动绑定的开源软件. 它可以在Java对象,XML文本,SQL数据表以及LDAP目录之间绑定.
- Digester原是Apache Jakarta Struts计划中的一部分，用来解析Web App中的XML配置文件，在开发一段时间之后，开发人员觉得这个小工具具有很普遍的使用场合，于是，将这个部分独立出来，放到Commons项目中。
由于Digester只是支持由XML到JavaBean的单向转换，而我的项目还需要能够从JavaBean到XML的转换。 所以我选择了Castor。
下面是Castor的例子
package org.scbit.lentinus.domain;
import java.util.ArrayList;
import java.util.List;
public
class SearchField {
private List<Table> tables;
public SearchField() {
this.tables = new ArrayList<Table>();
}
public List<Table> getTables() {
return
tables;
}
public
void addTable(Table table) {
this.tables.add(table);
}
}package org.scbit.lentinus.domain;
import java.util.ArrayList;
import java.util.List;
public
class Table {
private String tableDisplayName;
private String tableClass;
private List<Field> fields;
public Table() {
this.fields = new ArrayList<Field>();
}
public List<Field> getFields() {
return fields;
}
public void addField(Field field) {
this.fields.add(field);
}
public String getTableClass() {
return tableClass;
}
public void setTableClass(String tableClass) {
this.tableClass = tableClass;
}
public String getTableDisplayName() {
return tableDisplayName;
}
public void setTableDisplayName(String tableDisplayName) {
this.tableDisplayName = tableDisplayName;
}
}package org.scbit.lentinus.domain;
public
class Field {
public Field() {
}
private String fieldDisplay;
private String fieldName;
public String getFieldDisplay() {
return fieldDisplay;
}
public void setFieldDisplay(String fieldDisplay) {
this.fieldDisplay = fieldDisplay;
}
public String getFieldName() {
return fieldName;
}
public void setFieldName(String fieldName) {
this.fieldName = fieldName;
}
}转换代码
@Test
public void testField() throws Exception {
SearchField searchField = new SearchField();
Table table;
Field field;
table = new Table();
table.setTableDisplayName("级别信息");
table.setTableClass("TbBasicInfor");
field = new Field();
field.setFieldDisplay("拉丁学名");
field.setFieldName("latinName");
table.addField(field);
field = new Field();
field.setFieldDisplay("拉丁别名");
field.setFieldName("latinAlias");
table.addField(field);
searchField.addTable(table);
// write it out as XML
File file = new File(
"D:\\dev\\workplace\\eclipse_workspace\\LentinusEdodes\\WebRoot\\WEB-INF\\conf\\searchField.xml");
Writer writer = new OutputStreamWriter(new FileOutputStream(file),
"utf-8");
Marshaller marshaller = new Marshaller(writer);
marshaller.setEncoding("utf-8"); // 关键
marshaller.marshal(searchField);
// now restore the value and list what we get
Reader reader = new InputStreamReader(new FileInputStream(file),
"utf-8");
SearchField read = (SearchField) Unmarshaller.unmarshal(
SearchField.class, reader);
assertTrue(read.getTables().get(0).getTableDisplayName().equals("级别信息"));
writer.close();
reader.close();
}转换后的XML文件
searchField.xml
<?xml version="1.0" encoding="utf-8"?>
<search-field>
<tables xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:type="java:org.scbit.lentinus.domain.Table">
<fields xsi:type="java:org.scbit.lentinus.domain.Field">
<field-display>拉丁学名</field-display>
<field-name>latinName</field-name>
</fields>
<fields xsi:type="java:org.scbit.lentinus.domain.Field">
<field-display>拉丁别名</field-display>
<field-name>latinAlias</field-name>
</fields>
<table-class>TbBasicInfor</table-class>
<table-display-name>级别信息</table-display-name>
</tables>
</search-field>Castor使用起来还是比较简单的，但在读取中文的时候，要注意可能会有乱码问题，在它官方的FAQ中有相应的解释和解决方法。 > How do I set the encoding? Create a new instance of the Marshaller class and use the setEncoding method. You’ll also need to make sure the encoding for the Writer is set properly as well: … String encoding = “ISO-8859-1”; FileOutputStream fos = new FileOutputStream(“result.xml”); OutputStreamWriter osw = new OuputStreamWriter(fos, encoding); Marshaller marshaller = new Marshaller(osw); marshaller.setEncoding(encoding); …