java 解析 xml 字符串转换为实体，实体转换为 xml 字符串

1. XmlCommonUtil工具类代码如下：

import javax.xml.bind.JAXBContext;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;/*** XmlCommonUtil类用于XML字符串和对象之间的转换以及读取文件操作*/
public class XmlCommonUtil {/*** 将XML字符串转换为指定类的对象** @param xml   XML字符串* @param clazz 目标类的Class对象* @return 转换后的对象*/public static Object convertXmlStrToObject(String xml, Class clazz) throws Exception {JAXBContext context = JAXBContext.newInstance(clazz);Unmarshaller unmarshaller = context.createUnmarshaller();StringReader reader = new StringReader(xml);return unmarshaller.unmarshal(reader);}/*** 将实体对象转换为XML字符串** @param obj 实体对象* @return 转换后的字符串*/public static String convertObjectToXml(Object obj) throws Exception {StringWriter sw = new StringWriter();JAXBContext context = JAXBContext.newInstance(obj.getClass());Marshaller marshaller = context.createMarshaller();marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);marshaller.marshal(obj, sw);return sw.toString();}
}

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2. 模拟资源文件数据SqlList.xml：

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<sqls><sql>SELECT 1WHERE 1 = 1</sql><sql>SELECT 2WHERE 2 = 2</sql>
</sqls>

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3. 实体类SqlXml代码如下：

import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlType;
/*** SqlXml类用于表示XML中的sql元素*/
@XmlRootElement(name = "sqls")
@XmlType(propOrder = {"sql"})
public class SqlXml {private List<String> sql;@XmlElement(name = "sql")public List<String> getSql() {return sql;}public void setSql(List<String> sql) {this.sql = sql;}@Overridepublic String toString() {return "SqlXml{" +"sql=" + sql +'}';}
}

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4. main方法代码测试：

    public static void main(String[] args) throws Exception{// 读取指定文件中的XML内容String xmlStr = readFile("sql/SqlList.xml");// 将XML字符串转换为SqlXml对象SqlXml sqlXml = (SqlXml)convertXmlStrToObject(xmlStr, SqlXml.class);System.out.println(sqlXml);// 将SqlXml对象转换为XML字符串xmlStr = convertObjectToXml(sqlXml);System.out.println(xmlStr);}/*** 读取指定文件并返回文件内容** @param file 文件路径* @return 文件内容字符串*/public static String readFile(String file) {StringBuffer sb = null;try {InputStream inputStream = Thread.currentThread().getContextClassLoader().getResourceAsStream(file);BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));sb = new StringBuffer();String line = "";while ((line = bufferedReader.readLine()) != null) {sb.append(line + "\r\n");}bufferedReader.close();} catch (Exception e) {e.printStackTrace();}return sb.toString();}

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5. 执行结果：

SqlXml{sql=[SELECT 1WHERE 1 = 1, SELECT 2WHERE 2 = 2]}
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<sqls><sql>SELECT 1WHERE 1 = 1</sql><sql>SELECT 2WHERE 2 = 2</sql>
</sqls>Process finished with exit code 0

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