java JAXB + STAX（是一种针对XML的流式拉分析API）读取xml
JDK1.5需要添加jar包，1.6以后就不需要了
<dependency> <groupId>stax</groupId> <artifactId>stax-api</artifactId> <version>1.0.1</version> </dependency>
<dependency>
<groupId>javax.xml.bind</groupId>
<artifactId>jaxb-api</artifactId>
<version>2.2.12</version>
</dependency>
JAXB：JAXB 的全名是Java ™ Architecture for XML Binding
Classroom.java
1 public class Classroom { 2 private int id; 3 private String name; 4 private int grade; 5 6 public Classroom() { 7 super(); 8 // TODO Auto-generated constructor stub 9 } 10 11 public Classroom(int id, String name, int grade) { 12 super(); 13 this.id = id; 14 this.name = name; 15 this.grade = grade; 16 } 17 18 public int getId() { 19 return id; 20 } 21 22 public void setId(int id) { 23 this.id = id; 24 } 25 26 public String getName() { 27 return name; 28 } 29 30 public void setName(String name) { 31 this.name = name; 32 } 33 34 public int getGrade() { 35 return grade; 36 } 37 38 public void setGrade(int grade) { 39 this.grade = grade; 40 } 41 42 @Override 43 public String toString() { 44 // TODO Auto-generated method stub 45 return String.format("id:%d, name:%s, grade:%d", this.id, this.name, this.grade); 46 } 47 }
Student.java
1 @XmlRootElement 2 public class Student { 3 public int getId() { 4 return id; 5 } 6 7 public void setId(int id) { 8 this.id = id; 9 } 10 11 public String getName() { 12 return name; 13 } 14 15 public void setName(String name) { 16 this.name = name; 17 } 18 19 public int getAge() { 20 return age; 21 } 22 23 public void setAge(int age) { 24 this.age = age; 25 } 26 27 public Classroom getClassroom() { 28 return classroom; 29 } 30 31 public void setClassroom(Classroom classroom) { 32 this.classroom = classroom; 33 } 34 35 private int id; 36 private String name; 37 private int age; 38 private Classroom classroom; 39 40 public Student() { 41 super(); 42 // TODO Auto-generated constructor stub 43 } 44 45 public Student(int id, String name, int age, Classroom classroom) { 46 super(); 47 this.id = id; 48 this.name = name; 49 this.age = age; 50 this.classroom = classroom; 51 } 52 53 @Override 54 public String toString() { 55 // TODO Auto-generated method stub 56 return String.format("id:%d, name:%s, Classroom=>%s", this.id, this.name, this.classroom.toString()); 57 } 58 }
main方法：
1 public static void main(String[] args) throws JAXBException { 2 Student student = new Student(1, "大帅哥", 34, new Classroom(1, "计算机", 1)); 3 JAXBContext jaxbContext = JAXBContext.newInstance(Student.class); 4 Marshaller marshaller = jaxbContext.createMarshaller(); 5 marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true); //格式化输出 6 marshaller.marshal(student, System.out); 7 StringWriter stringWriter = new StringWriter(); 8 marshaller.marshal(student, stringWriter); 9 String xml = stringWriter.toString(); 10 Unmarshaller unmarshaller = jaxbContext.createUnmarshaller(); 11 student = (Student) unmarshaller.unmarshal(new StringReader(xml)); 12 System.out.println(student.toString()); 13 }
STAX：StAX是Streaming API for XML的缩写，是一种针对XML的流式拉分析API。
使用XMLStreamReader和XMLEventReader读取XML文件
1 <?xml version="1.0" encoding="UTF-8"?> 2 <company> 3 <depart title="Develop Group"> 4 <user name="Tom" age="28" gender="male" >Manager</user> 5 <user name="Lily" age="26" gender="female" /> 6 </depart> 7 <depart title="Test Group"> 8 <user name="Frank" age="32" gender="male" >Team Leader</user> 9 <user name="Bob" age="45" gender="male" /> 10 <user name="Kate" age="25" gender="female" /> 11 </depart> 12 </company>
JAVA代码
1 // 获得Stream解析器(指针读取器对象) 2 public static XMLStreamReader getStreamReader() { 3 XMLStreamReader reader = null; 4 String xmlFile = App.class.getResource("/").getFile() + "users.xml"; 5 XMLInputFactory factory = XMLInputFactory.newInstance(); 6 try { 7 reader = factory.createXMLStreamReader(new FileReader(xmlFile)); 8 } catch (FileNotFoundException e) { 9 e.printStackTrace(); 10 } catch (XMLStreamException e) { 11 e.printStackTrace(); 12 } 13 return reader; 14 } 15 16 // 获得Stream解析器(指针读取器对象),过滤器 17 public static XMLStreamReader getStreamReader(StreamFilter streamFilter) { 18 // 创建基于迭代器的指针读取器对象 19 XMLStreamReader filterReader = null; 20 String xmlFile = App.class.getResource("/").getFile() + "users.xml"; 21 XMLInputFactory factory = XMLInputFactory.newInstance(); 22 try { 23 XMLStreamReader reader = factory.createXMLStreamReader(new FileReader(xmlFile)); 24 filterReader = factory.createFilteredReader(reader, streamFilter); 25 } catch (FileNotFoundException e) { 26 e.printStackTrace(); 27 } catch (XMLStreamException e) { 28 e.printStackTrace(); 29 } 30 return filterReader; 31 } 32 33 // 列出所有用户名称 34 public static void listNames() { 35 // 创建基于迭代器的指针读取器对象 36 XMLStreamReader reader = App.getStreamReader(); 37 // 遍历XML文档 38 try { 39 while (reader.hasNext()) { 40 int event = reader.next(); 41 // 如果是元素的开始 42 if (event == XMLStreamConstants.START_ELEMENT) { 43 // 列出所有用户名称 44 if ("user".equalsIgnoreCase(reader.getLocalName())) { 45 System.out.println("Name:" + reader.getAttributeValue(null, "name")); 46 } 47 } 48 } 49 reader.close(); 50 } catch (XMLStreamException e) { 51 e.printStackTrace(); 52 } 53 } 54 55 public static void listNamesAndAges() { 56 XMLStreamReader reader = App.getStreamReader(); 57 try { 58 while (reader.hasNext()) { 59 // 跳过所有空白、注释或处理指令，到下一个START_ELEMENT 60 int event = reader.nextTag(); 61 if (event == XMLStreamConstants.START_ELEMENT) { 62 if ("user".equalsIgnoreCase(reader.getLocalName())) { 63 System.out.println("Name:" + reader.getAttributeValue(null, "name") + ";Age:" + reader.getAttributeValue(null, "age")); 64 } 65 } 66 } 67 reader.close(); 68 } catch (XMLStreamException e) { 69 e.printStackTrace(); 70 } 71 } 72 73 // 获得Event解析器(事件读取器对象) 74 public static XMLEventReader getEventReader() { 75 XMLEventReader reader = null; 76 String xmlFile = App.class.getResource("/").getFile() + "users.xml"; 77 XMLInputFactory factory = XMLInputFactory.newInstance(); 78 try { 79 reader = factory.createXMLEventReader(new FileReader(xmlFile)); 80 } catch (FileNotFoundException e) { 81 e.printStackTrace(); 82 } catch (XMLStreamException e) { 83 e.printStackTrace(); 84 } 85 return reader; 86 } 87 88 // 获得Event解析器(指针读取器对象),过滤器 89 public static XMLEventReader getEventReader(EventFilter eventFilter) { 90 // 创建基于迭代器的指针读取器对象 91 XMLEventReader filterReader = null; 92 String xmlFile = App.class.getResource("/").getFile() + "users.xml"; 93 XMLInputFactory factory = XMLInputFactory.newInstance(); 94 try { 95 XMLEventReader reader = factory.createXMLEventReader(new FileReader(xmlFile)); 96 filterReader = factory.createFilteredReader(reader, eventFilter); 97 } catch (FileNotFoundException e) { 98 e.printStackTrace(); 99 } catch (XMLStreamException e) { 100 e.printStackTrace(); 101 } 102 return filterReader; 103 } 104 105 @SuppressWarnings("rawtypes") 106 public static void listAllByXMLEventReader() { 107 // 创建基于迭代器的事件读取器对象 108 XMLEventReader reader = App.getEventReader(); 109 try { 110 // 遍历XML文档 111 while (reader.hasNext()) { 112 XMLEvent event = reader.nextEvent(); 113 // 如果事件对象是元素的开始 114 if (event.isStartElement()) { 115 // 转换成开始元素事件对象 116 StartElement start = event.asStartElement(); 117 // 打印元素标签的本地名称 118 System.out.print(start.getName().getLocalPart()); 119 // 取得所有属性 120 Iterator attrs = start.getAttributes(); 121 while (attrs.hasNext()) { 122 // 打印所有属性信息 123 Attribute attr = (Attribute) attrs.next(); 124 System.out.print(":" + attr.getName().getLocalPart() + "=" + attr.getValue()); 125 } 126 System.out.println(); 127 } 128 } 129 reader.close(); 130 } catch (XMLStreamException e) { 131 e.printStackTrace(); 132 } 133 } 134 135 public static void listUsersByStreamFilter() { 136 XMLStreamReader streamFilterReader = App.getStreamReader(new StreamFilter() { 137 public boolean accept(XMLStreamReader reader) { 138 try { 139 while (reader.hasNext()) { 140 int event = reader.next(); 141 // 只接受元素的开始 142 if (event == XMLStreamConstants.START_ELEMENT) { 143 // 只保留user元素 144 if ("user".equalsIgnoreCase(reader.getLocalName())) { 145 return true; 146 } 147 } 148 if (event == XMLStreamConstants.END_DOCUMENT) { 149 return true; 150 } 151 } 152 } catch (XMLStreamException e) { 153 e.printStackTrace(); 154 } 155 return false; 156 } 157 }); 158 try { 159 // 列出所有用户的名称 160 System.out.println(streamFilterReader.getLocalName()); 161 while (streamFilterReader.hasNext()) { 162 // 过滤工作已交由过滤器完成，这里不需要再做user的判断了 163 System.out.println("Name=" + streamFilterReader.getAttributeValue(null, "name")); 164 if (streamFilterReader.getEventType() != XMLStreamConstants.END_DOCUMENT) { 165 streamFilterReader.next(); 166 } 167 } 168 streamFilterReader.close(); 169 } catch (XMLStreamException e) { 170 e.printStackTrace(); 171 } 172 } 173 174 public static void listUsersByEventFilter() { 175 XMLEventReader eventFilterReader = App.getEventReader(new EventFilter() { 176 public boolean accept(XMLEvent event) { 177 // 如果事件对象是元素的开始 178 if (event.isStartElement()) { 179 // 转换成开始元素事件对象 180 StartElement start = event.asStartElement(); 181 // 打印元素标签的本地名称 182 return "user".equals(start.getName().getLocalPart()); 183 } 184 return false; 185 } 186 }); 187 try { 188 // 列出所有用户的名称 189 while (eventFilterReader.hasNext()) { 190 XMLEvent event = eventFilterReader.nextEvent(); 191 StartElement start = event.asStartElement(); 192 System.out.println(start.getName().getLocalPart()); 193 // 过滤工作已交由过滤器完成，这里不需要再做user的判断了 194 System.out.println("Name=" + start.getAttributeByName(new QName("name")).getValue()); 195 } 196 eventFilterReader.close(); 197 } catch (XMLStreamException e) { 198 e.printStackTrace(); 199 } 200 } 201 202 public static void main(String[] args) { 203 // listNames(); 204 // listNamesAndAges(); 205 // listAllByXMLEventReader(); 206 // listUsersByStreamFilter(); 207 // listUsersByEventFilter(); 208 }