自己手动实现简单spring-ioc容器
自己手动实现简单spring-ioc容器
解析xml用的包
<dependency> <groupId>org.jdom</groupId> <artifactId>jdom2</artifactId> <version>2.0.5</version> </dependency>
public class Bean { //存类路径名 private String className; //存对象 private Map<String, Object> params; public Bean() { } public Bean(String className, Map<String, Object> params) { this.className = className; this.params = params; } public String getClassName() { return className; } public void setClassName(String className) { this.className = className; } public Map<String, Object> getParams() { return params; } public void setParams(Map<String, Object> params) { this.params = params; } }
测试的类
public class Student { private Integer id; private Integer age; private String name; public Student() { } public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public Integer getAge() { return age; } public void setAge(Integer age) { this.age = age; } public String getName() { return name; } public void setName(String name) { this.name = name; } @Override public String toString() { return "Student{" + "id=" + id + ", age=" + age + ", name='" + name + '\'' + '}'; } }
public class Teacher { private Integer id; private Integer age; private String name; public Teacher() { } public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public Integer getAge() { return age; } public void setAge(Integer age) { this.age = age; } public String getName() { return name; } public void setName(String name) { this.name = name; } @Override public String toString() { return "Teacher{" + "id=" + id + ", age=" + age + ", name='" + name + '\'' + '}'; } }
测试xml
<beans> <bean id="Student" class="com.xiaocheng.Student"> <property name="id" value="1"/> <property name="age" value="10"/> <property name="name" value="aaa"/> </bean> <bean id="Teacher" class="com.xiaocheng.Teacher"> <property name="id" value="2"/> <property name="age" value="20"/> <property name="name" value="sss"/> </bean> </beans>
解析xml
public class FactoryBean { Map<String, Object> objectMap = new HashMap<>(); public List<Element> getxml() throws Exception { //新建xml解析器 SAXBuilder saxBuilder = new SAXBuilder(); //使用绝对路径 String path = "C:\\Users\\Administrator\\Documents\\myioc\\src\\main\\java\\resources\\applicationContext.xml"; // 构造文档对象 Document xmlDoc = saxBuilder.build(new FileInputStream(path)); //获取根元素 Element root = xmlDoc.getRootElement(); //获取根元素下所有名字为bean的元素 return root.getChildren("bean"); } public List<Bean> getxmllist() throws Exception { List<Bean> beans = new ArrayList<>(); for (Element e : getxml()) { //获取Element元素 //获取id属性的值 String id = e.getAttributeValue("id"); //获取property的class属性的值 String classname = e.getAttributeValue("class"); System.out.println(" id: " + id + " class: " + classname); Class<?> clazz = Class.forName(classname); //遍历bean下的所有properyt属性，并调用setter方法，将值注入给对应的属性 if (e.getChild("property") != null) { Map<String, Object> map = new HashMap<>(); for (Element p : e.getChildren("property")) { Integer valuetemp=null; String name = p.getAttributeValue("name"); String value = p.getAttributeValue("value"); Field[] fields = clazz.getDeclaredFields(); for (Field field : fields) { if (name.equals(field.getName())) { String type = split(field.getType().toString(), "\\."); if ("Integer".equals(type)) { valuetemp = Integer.valueOf(value); } //如需更多类型增加判断变量 } } // System.out.println(name + "=" + value); if (valuetemp!=null) { map.put(name, valuetemp); }else { map.put(name, value); } } Bean bean = new Bean(classname, map); beans.add(bean); } } return beans; }
public String split(String str, String separator) { //取到最后一段字符串 return str.split(separator)[str.split(separator).length - 1]; } public Map<String, Object> creatBeans() throws Exception { for (Bean item : getxmllist()) { String className = item.getClassName(); Map<String, Object> params = item.getParams(); Object object = createBean(className, params); objectMap.put(split(className, "\\."), object); } // /**返回对象的map*/ return objectMap; } /** * 创建Bean对象 * * @param className:类的全路径 * @param params:成员变量的名和值 */ private Object createBean(String className, Map<String, Object> params) throws Exception { Class<?> clazz = Class.forName(className); /*创建对象*/ Object object = clazz.newInstance(); // /**获取对象中的变量和value*/ Set<Map.Entry<String, Object>> entries = params.entrySet(); for (Map.Entry<String, Object> entry : entries) { // /**获取成员变量名称*/ String paramName = entry.getKey(); Method method = createMethod(clazz, paramName); // /*invoke()：函数调用*/ method.invoke(object, entry.getValue()); } return object; } /** * @param clazz:类的class对象 * @param name:成员变量名称 */ private Method createMethod(Class<?> clazz, String name) throws Exception { //拼接函数名称 StringBuilder methodName = new StringBuilder("set").append(name.substring(0, 1).toUpperCase()).append(name.substring(1)); Method method = null; // /**获取所有的成员函数*/ Method[] methods = clazz.getMethods(); ///**methodName：获取函数名称， getParameterTypes()：获取函数的参数列表*/ for (Method m : methods) { if (m.getName().equals(methodName.toString())) { // /**methodName：获取函数名称， getParameterTypes()：获取函数的参数列表*/ method = clazz.getMethod(methodName.toString(), m.getParameterTypes()); break; } } return method; } public static void main(String[] args) throws Exception { FactoryBean factoryBean = new FactoryBean(); Map<String, Object> objectMap = factoryBean.creatBeans(); Teacher teacher = (Teacher) objectMap.get("Teacher"); Student student = (Student) objectMap.get("Student"); System.out.println(teacher.toString()); System.out.println(student.toString()); } }
