jaxb操作xml文件（自定义xml namespace 前缀，可以有多个namespace）

最近在用jaxb 操作xml文件，所以我把代码整理了哈，里面实现的内容有：

1. 用jaxb把pojo对象转换成xml格式的字符串；

1.1. 生成的pojo对象在pojo文件夹里面（这个xml文件支持自定义namespace的前缀，可以有多个namespace）,主要的两个文件是

ObjectFactor,package-info.java

1.2. jaxb把pojo对象转换成xml的代码片段：

public static String marshal(Object pObj, String pEncoding) throws Exception {
    JAXBContext jaxbContext = JAXBContext.newInstance(pObj.getClass());
    Marshaller marshaller = jaxbContext.createMarshaller();
    marshaller.setProperty(Marshaller.JAXB_ENCODING, pEncoding);
    marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
    marshaller.setProperty(Marshaller.JAXB_FRAGMENT, false);
    //the propertyName(com.sun.xml.internal.bind.namespacePrefixMapper) may be different, it depends on your marshaller implement class
    marshaller.setProperty("com.sun.xml.internal.bind.namespacePrefixMapper", new NamespacePrefixMapper() {
        @Override
        public String getPreferredPrefix(String pNamespaceUri, String pPerfix, boolean pB) {
            if (NameSpace.NAMESPACE_CEB_URI.equals(pNamespaceUri)) {
                return NameSpace.NAMESPACE_CEB_PREFIX;
            } else if (NameSpace.NAMESPACE_XSI_URI.equals(pNamespaceUri)) {
                return NameSpace.NAMESPACE_XSI_PREFIX;
            }
            return pPerfix;
        }
    });
    StringWriter stringWriter = null;
    try {
        stringWriter = new StringWriter();
        marshaller.marshal(pObj, stringWriter);
        String xmlContent = stringWriter.toString();
        return xmlContent;
    } finally {
        if (stringWriter != null) {
            stringWriter.flush();
            stringWriter.close();
        }
    }
}

2. 根据xml格式的字符串生成新的xml文件；

public static void generateXmlFile(String pXmlContent, File pFile, String pEncoding) throws Exception {
    if (!pFile.exists()) {
        pFile.createNewFile();
    }
    FileOutputStream fos = null;
    OutputStreamWriter osw = null;
    try {
        fos = new FileOutputStream(pFile);
        osw = new OutputStreamWriter(fos, pEncoding);
        osw.write(pXmlContent);
    } finally {
        if (osw != null) {
            osw.flush();
            osw.close();
        }
        if (fos != null) {
            fos.flush();
            fos.close();
        }
    }
}

3. 复制xml文件，并且能够保持原来的xml文件格式跟新生成的xml文件格式一致(思路是先把xml文件读取成xml格式的字符串，然后再根据该字符串生成新的xml文件)；

public static boolean copyXmlFile(File pSourceFile, File pDestFile, String pEncoding) throws Exception {
    if (!pSourceFile.exists()) {
        throw new Exception("the sourceFile " + pSourceFile + " does not exist!");
    }
    if (!pDestFile.exists()) {
        pDestFile.createNewFile();
    }
    String fileContent = readXmlFile(pSourceFile, pEncoding);
    generateXmlFile(fileContent, pDestFile, pEncoding);
    return true;
}

public static String readXmlFile(File pFile, String pEncoding) throws Exception {
    InputStream is = null;
    BufferedReader br = null;
    try {
        is = new FileInputStream(pFile);
        br = new BufferedReader(new InputStreamReader(is, pEncoding));
        String line = null;
        StringBuilder sb = new StringBuilder();
        while ((line = br.readLine()) != null) {
            sb.append(line);
            sb.append(System.getProperty("line.separator"));
        }
        return sb.toString();
    } finally {
        if (br != null) {
            br.close();
        }
        if (is != null) {
            is.close();
        }
    }
}