XML解析以及增删改查的操作 4

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上一篇主要是贴了几种节点的代码,还有一个类Attribute代表属性,键值对的形式。直接贴代码

/*
 *   形如 btnEDate="2014-12-15"
 * */
public class Attribute implements Serializable{

    private static final long serialVersionUID = 4233216982243098384L;
    private String attributeName;
    private String attributeValue = "";
    
    public Attribute(){}
    
    public Attribute(String attributeName,String attributeValue){
        if(attributeName==null||attributeName.trim().equals("")){
            DocumentUtil.throwException(DocumentUtil.ARGUMENT_NULL);
        }
        this.attributeName = attributeName.trim();
        this.attributeValue = attributeValue==null?"":attributeValue;
    }
    
    @Override
    public String toString() {
        StringBuffer sb = new StringBuffer();
        sb.append(attributeName);
        sb.append("=\"");
        sb.append(attributeValue);
        sb.append("\"");
        return sb.toString();
    }
    
    public String getAttributeName() {
        return attributeName;
    }
    public void setAttributeName(String attributeName) {
        if(attributeName==null||attributeName.trim().equals("")){
            DocumentUtil.throwException(DocumentUtil.ARGUMENT_NULL);
        }
        this.attributeName = attributeName.trim();
    }
    public String getAttributeValue() {
        return attributeValue;
    }
    public void setAttributeValue(String attributeValue) {
        if(attributeValue==null){
            DocumentUtil.throwException("空指针!");
        }
        this.attributeValue = attributeValue;
    }
    
    @Override
    public boolean equals(Object obj) {
        if(this==obj){
            return true;
        }
        try{
            Attribute att = (Attribute)obj;
            return attributeName.equals(att.attributeName);
        }catch(Exception e){
            return false;
        }
    }
}

下面就是写document类了,因为需要的“材料”都准备好了。

/** xml文档对象 */
public class Document implements Serializable {

    /**
     * 序列化版本号
     */
    private static final long serialVersionUID = 1353311427641889804L;
    /*
     * <?xml version="1.0" encoding="UTF-8"?>
     */
    public final static String DEFAULT_VERSION = "1.0";
    public final static String UTF8 = "UTF-8";
    public final static String DEFAULT_ENCODING = UTF8;
    /** 版本号 */
    private String version = DEFAULT_VERSION;
    /** 编码 */
    private String encoding = DEFAULT_ENCODING;
    public final static String GBK = "gbk";
    public final static String GB2312 = "gb2312";
    public final static String ISO8859_1 = "ISO8859-1";
    
    /**文档属性换行*/
    public static final int NEW_LINE = 0x0;
    /**文档属性不换行*/
    public static final int SINGLE_LINE = 0x1;
    /**
     * 文档属性是否换行(格式化用)
     * */
    public int attributeLine = SINGLE_LINE;
    
    /** 子节点列表,其中有且只有一个根节点,可能还有注释节点 */
    private List<Node> nodeList = new ArrayList<Node>();
    /**
     * 类似<?xml version="1.0" encoding="utf-8" standalone="no"?>,可能还有其他内容
     * */
    private final List<Attribute> headAttributeList = new ArrayList<Attribute>();

    public Document() {
        init();
    }
    
    private void init() {
        headAttributeList.add(new Attribute("version",DEFAULT_VERSION));
        headAttributeList.add(new Attribute("encoding",DEFAULT_ENCODING));
    }

    public void addAttribute(Attribute attribute){
        if(attribute==null){
            return;
        }
        int flag = 0;
        for(int i=0;i<headAttributeList.size();i++){
            Attribute att = headAttributeList.get(i);
            if(att.equals(attribute)){
                headAttributeList.remove(i);
                headAttributeList.add(i,attribute);
                flag++;
                break;
            }
        }
        if(flag == 0){
            headAttributeList.add(attribute);
        }
        if(attribute.getAttributeName().equalsIgnoreCase("encoding")){
            encoding = attribute.getAttributeValue();
        }
    }

    public void setVersion(String version) {
        if (version == null || ((version = version.trim()).equals(""))) {
            version = DEFAULT_VERSION;
        }
        this.version = version;
        addAttribute(new Attribute("version",this.version));
    }

    public String getEncoding() {
        return encoding;
    }

    public void setEncoding(String encoding) {
        this.encoding = encoding == null
                || (encoding = encoding.trim()).length() == 0 ? DEFAULT_ENCODING
                : encoding.trim();
        addAttribute(new Attribute("encoding",this.encoding));
    }

    public List<Node> getNodeList() {
        return nodeList;
    }

    /** 设置节点list*/
    public void setNodeList(List<Node> nodeList) {
        if (nodeList == null || nodeList.size() == 0) {
            DocumentUtil.throwException("参数不能为空!");
        }
        int flag = 0;
        for (Node node : nodeList) {
            if(node instanceof TextNode){
                DocumentUtil.throwException("文档对象不能包含文本节点!");
            }
            if (node instanceof Element) {
                flag++;
            }
        }
        if (flag != 1) {
            DocumentUtil.throwException("只能有且只有一个根节点!");
        }
        this.nodeList = nodeList;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        try {
            Document document = (Document) obj;
            return version.equalsIgnoreCase(document.version)
                    && encoding.equalsIgnoreCase(document.encoding)
                    && nodeList.equals(document.nodeList);
        } catch (Exception e) {
            return false;
        }
    }

    public Element getRootNode() {
        if (nodeList == null || nodeList.size() == 0) {
            return null;
        }
        for (Node node : nodeList) {
            if (node != null && node instanceof Element) {
                return (Element) node;
            }
        }
        return null;
    }

    /**
     * 设置根节点
     * */
    public boolean setRootNode(Element root) {
        if (root == null) {
            return false;
        }
        root.domFather = this;
        if (hasSetRootNode()) {
            for (int i = 0; i < nodeList.size(); i++) {
                Node node = nodeList.get(i);
                if (node != null && node instanceof Element) {
                    nodeList.remove(i);
                    nodeList.add(i,root);
                    node.domFather = null;
                    return true;
                }
            }
        }
        return nodeList.add(root);
    }

    /**
     * 设置根节点
     * */
    public boolean setRootNode(Element root,int index) {
        if (root == null) {
            return false;
        }
        root.domFather = this;
        if (hasSetRootNode()) {
            for (int i = 0; i < nodeList.size(); i++) {
                Node node = nodeList.get(i);
                if (node != null && node instanceof Element) {
                    nodeList.remove(i);
                    nodeList.add(index,root);
                    node.domFather = null;
                    return true;
                }
            }
        }
        nodeList.add(index,root);
        return true;
    }

    @Override
    public int hashCode() {
        return super.hashCode();
    }

    @Override
    public String toString() {
        StringBuffer sb = new StringBuffer();
        if(headAttributeList!=null&&headAttributeList.size()>0){
            sb.append("<?xml");
            if(attributeLine == SINGLE_LINE){
                for(int i=0;i<headAttributeList.size();i++){
                    Attribute attribute = headAttributeList.get(i);
                    sb.append(" "+attribute.toString());
                }
            }else if(attributeLine == NEW_LINE){
                for(int i=0;i<headAttributeList.size();i++){
                    Attribute attribute = headAttributeList.get(i);
                    if(i==0){
                        sb.append(" "+attribute.toString());
                    }else{
                        sb.append("\n"+"    "+attribute.toString());
                    }
                }
            }
            sb.append("?>");
        }
        for (Node node : nodeList) {
            sb.append("\n");
            sb.append(node.toString());
        }
        return sb.toString();
    }

    public boolean addNode(Node node) {
        if (node == null) {
            return false;
        }
        if(node instanceof TextNode){
            DocumentUtil.throwException("文档不能添加文本节点!");
        }
        if (node instanceof AnnotationNode) {
            node.domFather = this;
            return nodeList.add(node);
        } else {
            Element element = (Element) node;
            return setRootNode(element);
        }
    }

    public boolean hasSetRootNode() {
        return getRootNode() != null;
    }

    /**
     * 保存到文件
     * */
    public void saveTo(File file) throws IOException {
        BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file),encoding));
        writer.write(toString());
        if(writer!=null){
            writer.flush();
            writer.close();
            writer = null;
        }
    }
    
    /**
     * 保存到文件
     * */
    public void saveTo(String filename) throws IOException{
        saveTo(new File(filename));
    }

    public List<Attribute> getHeadAttributeList() {
        return headAttributeList;
    }

    /**
     * 文档格式化
     * */
    public void setRootNodeAttributeLine(boolean singleLine){
        Element root = getRootNode();
        if(root!=null){
            root.setAll_attributeLine(singleLine);
        }
    }
    
    /**
     * 移除节点
     * */
    public boolean remove(Node node){
        DocumentUtil.throwExceptionIfNull(node);
        if(nodeList==null||nodeList.size()==0){
            DocumentUtil.throwException(new RuntimeException("空指针!"));
        }
        if(nodeList.remove(node)){
            node.domFather = null;
            return true;
        }
        return false;
    }
    
    /**
     * 得到第一个子节点
     * */
    public Node getFirstChild(){
        if(nodeList==null||nodeList.isEmpty()){
            return null;
        }
        return nodeList.get(0);
    }
    
    /**
     * 得到最后一个子节点
     * */
    public Node getLastChild(){
        if(nodeList==null||nodeList.isEmpty()){
            return null;
        }
        return nodeList.get(nodeList.size()-1);
    }
}

这个类主要是对document对象的操作。 操作完了就可以把document对象保存到xml文件,saveTo方法就是做这个的。总的来说创建文档以及对文档的写操作都不难。主要是建好数据模型。有了思路所以编程就很简单了。最复杂的是她的逆向需求,即读取xml文件解析得到document文档对象。见下一篇

原文链接:https://www.f2er.com/xml/299356.html

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