株洲网站制作公司竞价排名的优缺点

1 XML解析器对比

1. DOM解析器：

○ 优点：易于使用，提供完整的文档树，可以方便地修改和遍历XML文档。
○ 缺点：对大型文档消耗内存较多，加载整个文档可能会变慢。
○ 适用场景：适合小型XML文档或需要多次访问和修改XML内容的情况。

2. SAX解析器：

○ 优点：逐个处理XML元素，节省内存，适用于一次性遍历大型XML文档。
○ 缺点：编写处理事件的代码可能会相对复杂，不适合需要频繁修改XML内容的情况。
○ 适用场景：适合大型XML文档的读取、分析和提取数据。

3. StAX解析器：

○ 优点：结合了DOM和SAX的优点，提供了灵活的编程模型，适用于流式处理和部分内存加载。
○ 缺点：可能比纯粹的SAX稍微复杂一些。
○ 适用场景：适合需要处理中等大小的XML文档，同时保持较低内存占用的情况。

4. XPath解析器：

○ 优点：提供了强大的查询功能，能够方便地定位XML文档中的元素和数据。
○ 缺点：可能会稍微降低性能，特别是在复杂的查询情况下。
○ 适用场景：适合需要定位和提取特定数据的情况，可以减少手动遍历和解析的工作。

5. JSON对应XML解析器：

○ 优点：可以将XML数据转换为JSON格式，利用JSON解析器处理。
○ 缺点：可能会导致数据结构转换复杂性，不是所有情况下都适用。
○ 适用场景：当您的应用程序使用JSON格式处理数据，但需要处理XML数据时，可以考虑此类解析器。

解析的jacoco XML数据量较多 行数至几十万行 XML大小为 数十M
选择SAX解析器进行解析

2 解析思路

SAX可以逐行处理标签

/*** @author xieyan* @date 2023-08-22 16:13*/
public class JacocoXmlConstant {public static final String COUNTER = "counter";public static final String METHOD = "method";public static final String CLASS = "class";public static final String SOURCEFILE = "sourcefile";public static final String SOURCEFILE_NAME = "name";public static final String COUNTER_TYPE = "type";public static final String COUNTER_MISSED = "missed";public static final String COUNTER_COVERED = "covered";public static final String METHOD_NAME = "name";public static final String METHOD_DESC = "desc";public static final String CLASS_NAME = "name";public static final String CLASS_SOURCEFILENAME = "sourcefilename";public static final String REPORT_NAME = "name";public static final String PACKAGE_NAME = "name";public static final String REPORT = "report";public static final String PACKAGE = "package";public static final String SESSIONINFO = "sessioninfo";public static final String LINE = "line";public static final String INSTRUCTION_TYPE = "INSTRUCTION";public static final String BRANCH_TYPE = "BRANCH";public static final String LINE_TYPE = "LINE";public static final String COMPLEXITY_TYPE = "COMPLEXITY";public static final String METHOD_TYPE = "METHOD";public static final String CLASS_TYPE = "CLASS";}import lombok.Getter;
import org.xml.sax.Attributes;
import org.xml.sax.helpers.DefaultHandler;import java.util.List;import static com.jacoco.xml.JacocoXmlConstant.*;/*** 解析xml文件** @author xieyan*/
@Getter
public class ParseXmlHandler extends DefaultHandler {private Report report;private Package currentPackage;private Clazz currentClass;private Method currentMethod;private Counter currentCounter;private String sourcefile;/*** 开始解析元素时触发*/@Overridepublic void startElement(String uri, String localName, String qName, Attributes attributes) {switch (qName) {// 跳过 sessioninfo 和 linecase SESSIONINFO:case LINE:return;// 解析reportcase REPORT:report = new Report();report.setName(attributes.getValue(REPORT_NAME));break;// 解析packagecase PACKAGE:currentPackage = new Package();currentPackage.setName(attributes.getValue(PACKAGE_NAME));if (report != null) {report.addPackage(currentPackage);}break;// 解析classcase CLASS:currentClass = new Clazz();currentClass.setName(attributes.getValue(CLASS_NAME));currentClass.setSourcefilename(attributes.getValue(CLASS_SOURCEFILENAME));if (currentPackage != null) {currentPackage.addClass(currentClass);}break;// 解析methodcase METHOD:currentMethod = new Method();currentMethod.setName(attributes.getValue(METHOD_NAME));currentMethod.setDesc(attributes.getValue(METHOD_DESC));if (currentClass != null) {currentClass.addMethod(currentMethod);}break;// 解析sourcefilecase SOURCEFILE:sourcefile = attributes.getValue(SOURCEFILE_NAME);break;// 解析countercase COUNTER:currentCounter = new Counter();currentCounter.setType(attributes.getValue(COUNTER_TYPE));currentCounter.setMissed(Integer.parseInt(attributes.getValue(COUNTER_MISSED)));currentCounter.setCovered(Integer.parseInt(attributes.getValue(COUNTER_COVERED)));// 绑定counter 到对应的元素bindCounter();break;default:break;}}/*** 结束解析元素时触发*/@Overridepublic void endElement(String uri, String localName, String qName) {switch (qName) {case SESSIONINFO:case LINE:// 跳过 sessioninfo 和 linereturn;case SOURCEFILE:// 避免重复加入 counter 到 pagesourcefile = null;break;case REPORT:// 计算总的覆盖率Coverage coverageReport = caculateCoverage(report.getReportCounters());report.setReportCoverage(coverageReport);break;case PACKAGE:// 计算 package 覆盖率if (currentPackage != null) {Coverage coveragePackage = caculateCoverage(currentPackage.getPackageCounters());currentPackage.setPackageCoverage(coveragePackage);currentPackage = null;}break;case CLASS:// 计算 class 覆盖率if (currentClass != null) {Coverage coverageClass = caculateCoverage(currentClass.getClazzCounters());currentClass.setClazzCoverage(coverageClass);currentClass = null;}break;case METHOD:// 计算 method 覆盖率if (currentMethod != null) {Coverage coverageMethod = caculateCoverage(currentMethod.getMethodCounters());currentMethod.setMethodCoverage(coverageMethod);currentMethod = null;}break;case COUNTER:currentCounter = null;break;default:break;}}/*** 绑定counter 到对应的元素*/private void bindCounter() {// counter 属于 methodif (currentMethod != null) {currentMethod.addCounter(currentCounter);}// counter 属于 classelse if (currentClass != null) {currentClass.addCounter(currentCounter);}// counter 属于 packageelse if (currentPackage != null) {// 跳过sourcefile里的counter 避免重复加入if (sourcefile == null) {currentPackage.addCounter(currentCounter);}}// counter 属于 reportelse if (report != null) {report.addCounter(currentCounter);}}/*** 计算覆盖率*/private Coverage caculateCoverage(List<Counter> counterList) {Coverage result = new Coverage();for (Counter counter : counterList) {String type = counter.getType().toUpperCase();String coverage = processResult(counter);setCoverageByType(result, type, coverage);}return result;}private void setCoverageByType(Coverage result, String type, String coverage) {switch (type) {// 指令覆盖率case INSTRUCTION_TYPE:result.setInstructionCoverage(coverage);break;// 行覆盖率case LINE_TYPE:result.setLineCoverage(coverage);break;// 分支覆盖率case BRANCH_TYPE:result.setBranchCoverage(coverage);break;// 圈复杂度覆盖率case COMPLEXITY_TYPE:result.setComplexityCoverage(coverage);break;// 方法覆盖率case METHOD_TYPE:result.setMethodCoverage(coverage);break;// 类覆盖率case CLASS_TYPE:result.setClassCoverage(coverage);break;default:break;}}/*** 处理覆盖率结果* 保留两位小数 例如 99.99%*/private String processResult(Counter counter) {int missed = counter.getMissed();int covered = counter.getCovered();double coverage = (double) covered / (missed + covered);double coveragePercentage = coverage * 100;return String.format("%.2f%%", coveragePercentage);}}import lombok.Data;import java.util.ArrayList;
import java.util.List;/*** @author xieyan*/
@Data
public class Clazz {private String name;private String sourcefilename;private final List<Method> methods = new ArrayList<>();private final List<Counter> clazzCounters = new ArrayList<>();private Coverage clazzCoverage;public void addMethod(Method method) {methods.add(method);}public void addCounter(Counter counter) {clazzCounters.add(counter);}}import lombok.Data;/*** @author xieyan*/
@Data
public class Counter {private String type;private int missed;private int covered;}import lombok.Data;/*** 覆盖率统计* @author xieyan* @date 2021-08-22 16:13*/
@Data
public class Coverage {/*** 指令覆盖率*/private String instructionCoverage;/** * 分支覆盖率*/private String branchCoverage;/*** 行覆盖率*/private String lineCoverage;/*** 圈复杂度覆盖率*/private String complexityCoverage;/*** 方法覆盖率 */private String methodCoverage;/*** 类覆盖率*/private String classCoverage;
}Method
import lombok.Data;import java.util.ArrayList;
import java.util.List;/*** @author xieyan*/
@Data
public class Method {private String name;private String desc;private final List<Counter> methodCounters = new ArrayList<>();private Coverage methodCoverage;public void addCounter(Counter counter) {methodCounters.add(counter);}}import lombok.Data;import java.util.ArrayList;
import java.util.List;/*** @author xieyan*/
@Data
public class Package {private String name;private final List<Clazz> classes = new ArrayList<>();private final List<Counter> packageCounters = new ArrayList<>();private Coverage packageCoverage;public void addClass(Clazz clazz) {classes.add(clazz);}public void addCounter(Counter counter) {packageCounters.add(counter);}}@Data
public class Report {private String name;private final List<Package> packages = new ArrayList<>();private final List<Counter> reportCounters = new ArrayList<>();private Coverage reportCoverage;public void addPackage(Package pkg) {packages.add(pkg);}public void addCounter(Counter counter) {reportCounters.add(counter);}}import lombok.extern.slf4j.Slf4j;
import org.xml.sax.SAXException;import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;/*** 解析jacoco覆盖率报告工具类* @author xieyan* @date 2023-08-22 16:38*/
@Slf4j
public class ParseJacocoXmlUtil {/*** 解析jacoco覆盖率报告** @param xmlPath jacoco覆盖率报告路径* @return 解析后的报告对象，解析失败时返回null*/public static Report parse(String xmlPath) {try {SAXParserFactory factory = SAXParserFactory.newInstance();// 禁用DTD验证factory.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);SAXParser saxParser = factory.newSAXParser();// 读取xml文件File xmlFile = new File(xmlPath);ParseXmlHandler handler = new ParseXmlHandler();try (InputStream inputStream = xmlFile.toURI().toURL().openStream()) {// 解析XML文件saxParser.parse(inputStream, handler);return handler.getReport();}} catch (ParserConfigurationException | SAXException | IOException e) {log.error("解析jacoco xml 覆盖率报告失败", e);}return null;}
}public class SaxParsingToJavaObjectExample {public static void main(String[] args) {// 指定XML文件路径String xmlFilePath = "D:\\tmp\\jacoco.xml";//String xmlFilePath = "F:\\temp\\a.xml";Report report = ParseJacocoXmlUtil.parse(xmlFilePath);Optional.ofNullable(report).ifPresent(SaxParsingToJavaObjectExample::export);}public static void export(Report report) {for (Package pkg : report.getPackages()) {System.out.println("Package Name: " + pkg.getName());for (Clazz clazz : pkg.getClasses()) {System.out.println("Class Name: " + clazz.getName());for (Method method : clazz.getMethods()) {System.out.println("Method Name: " + method.getName());System.out.println("Method Description: " + method.getDesc());for (Counter counter : method.getMethodCounters()) {System.out.println("Counter Type: " + counter.getType());System.out.println("Counter Missed: " + counter.getMissed());System.out.println("Counter Covered: " + counter.getCovered() + "\n");}System.out.println("==================== Method ==========================================");}}}}
}