XMLObject 简易xml格式接口数据生成和解析工具

简单的请求封装，相当于封装了Book对象，但比Book对象参数更灵活

XMLObject xml = new XMLObject("book");
xml.add("author", "Jack");
xml.add("name", "JavaScript");
XMLObject store = new XMLObject("store");
store.add("city", "NewYourk");
xml.add(store);
System.out.println(xml.toString());
//<book><author>Jack</author><name>JavaScript</name><store><city>NewYourk</city></store></book>

包含多个store元素的封装，

store = store.clone(); //复制store，否则之前的会被覆盖
store.update("city", "Washington"); //更新已有元素city的值，NewYourk => Washington
store.add("country", "America"); //第二个store可以灵活地添加元素
xml.add(store);
System.out.println(xml.toString());
//<book><author>Jack</author><name>JavaScript</name><store><city>NewYourk</city></store><store><city>Washington</city><country>America</country></store></book>

解析xml，获取值

xml = XMLObject.fromString(xml.toString());
System.out.println(xml.get("name")); //JavaScript
List<XMLObject> nodes = xml.getNodes("store");
for(XMLObject node : nodes) {
	System.out.println(node.toString());
}
//<store><city>NewYourk</city></store>
//<store><city>Washington</city><country>America</country></store>

public class XMLObject implements Cloneable {
	private String name;
	private List<Object> nodes = new LinkedList<>();
	
	/**
	 * @param name 不能包含特殊字符</>
	 */
	public XMLObject(String name) {
		if(name!=null && name.matches("[^</>]+")) {
			this.name = name;
		}else {
			throw new IllegalArgumentException("bad name: "+name);
		}
	}
	public String getName() {
		return name;
	}
	public void add(String field, String value) {
		nodes.add(new FieldValue(field, value));
	}
	public void add(XMLObject node) {
		nodes.add(node);
	}
	public boolean update(String field, String value) {
		for(Object node : nodes) {
			if(node instanceof FieldValue) {
				FieldValue fv = (FieldValue)node;
				if(fv.getField().equals(field)) {
					fv.value = value;
					return true;
				}
			}
		}
		return false;
	}
	public String get(String field) {
		for(Object node : nodes) {
			if(node instanceof FieldValue) {
				FieldValue fv = (FieldValue)node;
				if(fv.getField().equals(field))
					return fv.getValue();
			}
		}
		return null;
	}
	public XMLObject getNode(String field) {
		for(Object node : nodes) {
			if(node instanceof XMLObject) {
				XMLObject obj = (XMLObject)node;
				if(obj.name.equals(field))
					return obj;
			}
		}
		return null;
	}
	public List<XMLObject> getNodes(String field) {
		List<XMLObject> objs = new LinkedList<>();
		for(Object node : nodes) {
			if(node instanceof XMLObject) {
				XMLObject obj = (XMLObject)node;
				if(obj.name.equals(field))
					objs.add(obj);
			}
		}
		return objs;
	}
	
	public String toString() {
		StringBuilder xml = new StringBuilder("<"+name+">");
		for(Object node : nodes) {
			if(node instanceof FieldValue) {
				FieldValue fv = (FieldValue)node;
				xml.append("<"+fv.field+">");
				xml.append(fv.value);
				xml.append("</"+fv.field+">");
			}else if(node instanceof XMLObject) {
				XMLObject obj = (XMLObject)node;
				xml.append(obj.toString());
			}
		}
		xml.append("</"+name+">");
		return xml.toString();
	}
	
	protected XMLObject clone() {
		XMLObject xml = new XMLObject(name);
		xml.nodes = new LinkedList<>();
		for(Object node : this.nodes) {
			if(node instanceof FieldValue) {
				FieldValue fv = (FieldValue)node;
				xml.add(fv.field, fv.value);
			}else  if(node instanceof XMLObject) {
				XMLObject obj = (XMLObject)node;
				obj = obj.clone();
				xml.add(obj);
			}
		}
		return xml;
	}
	public static String header() {
		return "<?xml version="1.0" encoding="UTF-8"?>";
	}
	public static XMLObject fromString(String xml) {
		XMLObject obj = null;
		StringBuilder field = new StringBuilder(), value = new StringBuilder();
		if(xml.startsWith(header())) xml = xml.substring(header().length());
		boolean tag = false, start = false;
		char[] cs = xml.toCharArray();
		for(int i = 0; i<cs.length; i++) {
			char c = cs[i];
			switch(c) {
			case '<':
				tag = true;
				start = true;
				if(field.length()>0 && value.length()==0) {
					int end = xml.indexOf("</"+field+">", i);
					String subXml = xml.substring(i-field.length()-2, end+field.length()+3);
					XMLObject sub = fromString(subXml);
					obj.add(sub);
					i = end+field.length()+3;
					field.delete(0, field.length());
				}
				break;
			case '>':
				tag = false;
				if(start) {
					if(obj==null) {
						obj = new XMLObject(field.toString());
						field.delete(0, field.length());
					}
				}else {
					if(field.length()>0 && field.length()>0) {
						obj.add(field.toString(), value.toString());
						field.delete(0, field.length());
						value.delete(0, value.length());
					}
				}
				break;
			case '/':
				start = false;
				break;
			default:
				if(tag && start) field.append(c) ;
				if(!tag) value.append(c);
				break;
			}
		}
		return obj;
	}
	
	public static class FieldValue {
		private String field;
		private String value;
		/**
		 * @param field 不能包含特殊字符</>
		 * @param value 不能包含特殊字符</>
		 */
		public FieldValue(String field, String value) {
			if(field!=null && value!=null) {
				boolean b = field.matches("[^</>]+");
				if(b) b = value.matches("[^</>]+");
				else throw new IllegalArgumentException("bad field: "+field);
				
				if(b) { this.field = field; this.value = value; }
				else throw new IllegalArgumentException("bad value: "+value);
			}else {
				throw new IllegalArgumentException("bad field or value: "+field+","+value);
			}
		}
		public String getField() {
			return field;
		}
		public String getValue() {
			return value;
		}
	}
}


原文地址：http://www.xlongwei.com/detail/15032713