mybatis-XMLMapperEntityResolver 找对应的dtd文件
URL和mybatis的dtd文件用map做了一个映射
每个配置文件中有一个PUBLICID和SYSTEMID 这个是我们注册的key
而EntityResolver是一个接口 实现这个接口可以去寻找dtd文件
public class XMLMapperEntityResolver implements EntityResolver {
/**
* 用来做映射处理KEY和DTD文件的映射 可以理解为策略模式
*/
private static final Map
private static final String IBATIS_CONFIG_PUBLIC = "-//ibatis.apache.org//DTD Config 3.0//EN"
.toUpperCase(Locale.ENGLISH);
private static final String IBATIS_CONFIG_SYSTEM = "http://ibatis.apache.org/dtd/ibatis-3-config.dtd"
.toUpperCase(Locale.ENGLISH);
private static final String IBATIS_MAPPER_PUBLIC = "-//ibatis.apache.org//DTD Mapper 3.0//EN"
.toUpperCase(Locale.ENGLISH);
private static final String IBATIS_MAPPER_SYSTEM = "http://ibatis.apache.org/dtd/ibatis-3-mapper.dtd"
.toUpperCase(Locale.ENGLISH);
private static final String MYBATIS_CONFIG_PUBLIC = "-//mybatis.org//DTD Config 3.0//EN"
.toUpperCase(Locale.ENGLISH);
private static final String MYBATIS_CONFIG_SYSTEM = "http://mybatis.org/dtd/mybatis-3-config.dtd"
.toUpperCase(Locale.ENGLISH);
private static final String MYBATIS_MAPPER_PUBLIC = "-//mybatis.org//DTD Mapper 3.0//EN"
.toUpperCase(Locale.ENGLISH);
private static final String MYBATIS_MAPPER_SYSTEM = "http://mybatis.org/dtd/mybatis-3-mapper.dtd"
.toUpperCase(Locale.ENGLISH);
private static final String MYBATIS_CONFIG_DTD = "org/mybatis/builder/xml/mybatis-3-config.dtd";
private static final String MYBATIS_MAPPER_DTD = "org/mybatis/builder/xml/mybatis-3-mapper.dtd";
static {
doctypeMap.put(IBATIS_CONFIG_SYSTEM, MYBATIS_CONFIG_DTD);
doctypeMap.put(IBATIS_CONFIG_PUBLIC, MYBATIS_CONFIG_DTD);
doctypeMap.put(IBATIS_MAPPER_SYSTEM, MYBATIS_MAPPER_DTD);
doctypeMap.put(IBATIS_MAPPER_PUBLIC, MYBATIS_MAPPER_DTD);
doctypeMap.put(MYBATIS_CONFIG_SYSTEM, MYBATIS_CONFIG_DTD);
doctypeMap.put(MYBATIS_CONFIG_PUBLIC, MYBATIS_CONFIG_DTD);
doctypeMap.put(MYBATIS_MAPPER_SYSTEM, MYBATIS_MAPPER_DTD);
doctypeMap.put(MYBATIS_MAPPER_PUBLIC, MYBATIS_MAPPER_DTD);
}
/**
* 返回PUBLICID SYSTEMID所对应的DTD文件
*/
public InputSource resolveEntity(String publicId, String systemId) throws SAXException {
if (publicId != null) {
publicId = publicId.toUpperCase(Locale.ENGLISH);
}
if (systemId != null) {
systemId = systemId.toUpperCase(Locale.ENGLISH);
}
InputSource source = null;
try {
String path = doctypeMap.get(publicId);
source = getInputSource(path, source);
if (source == null) {
path = doctypeMap.get(systemId);
source = getInputSource(path, source);
}
} catch (Exception e) {
throw new SAXException(e.toString());
}
return source;
}
/**
* SAX 解析器将使用 InputSource 对象来确定如何读取 XML 输入
* @param path
* @param source
* @return
*/
private InputSource getInputSource(String path, InputSource source) {
if (path != null) {
InputStream in;
try {
/**
* 通过自定义类加载器查找资源
*/
in = Resources.getResourceAsStream(path);
source = new InputSource(in);
} catch (IOException e) {
// ignore, null is ok
}
}
return source;
}
}