packagecom.fr.data;
importjava.io.File;
importjava.util.ArrayList;
importjava.util.List;
importjavax.xml.parsers.SAXParser;
importjavax.xml.parsers.SAXParserFactory;
importorg.xml.sax.Attributes;
importorg.xml.sax.SAXException;
importorg.xml.sax.helpers.DefaultHandler;
importcom.fr.base.FRContext;
importcom.fr.data.AbstractDataModel;
importcom.fr.general.ComparatorUtils;
importcom.fr.general.data.TableDataException;
/**
* XMLParseDemoDataModel
*
* DataModel是获取数据的接口
*
* 这里通过init方法一次性取数后，构造一个二维表对象来实现DataModel的各个取数方法
*/
publicclass XMLParseDemoDataModel extends AbstractDataModel {
public static final int COLUMN_TYPE_STRING= 0;
public static final int COLUMN_TYPE_INTEGER= 1;
public static final int COLUMN_TYPE_BOOLEAN= 2;
protected List row_list = null;
private String[] xPath;
private XMLColumnNameType4Demo[]columns;
private String filePath;
public XMLParseDemoDataModel(Stringfilename, String[] xPath,
XMLColumnNameType4Demo[] columns){
this.filePath = filename;
this.xPath = xPath;
this.columns = columns;
}
/**
* 取出列的数量
*/
public int getColumnCount() throwsTableDataException {
return columns.length;
}
/**
* 取出相应的列的名称
*/
public String getColumnName(intcolumnIndex) throws TableDataException {
if (columnIndex < 0 || columnIndex>= columns.length)
return null;
String columnName =columns[columnIndex] == null ? null
:columns[columnIndex].getName();
return columnName;
}
/**
* 取出得到的结果集的总的行数
*/
public int getRowCount() throwsTableDataException {
this.init();
return row_list.size();
}
/**
* 取出相应位置的值
*/
public Object getValueAt(int rowIndex, intcolumnIndex)
throws TableDataException {
this.init();
if (rowIndex < 0 || rowIndex >=row_list.size() || columnIndex < 0
|| columnIndex >=columns.length)
return null;
return ((Object[])row_list.get(rowIndex))[columnIndex];
}
/**
* 释放一些资源，取数结束后，调用此方法来释放资源
*/
public void release() throws Exception{
if (this.row_list != null) {
this.row_list.clear();
this.row_list = null;
}
}
/**************************************************** */
/** ***********以上是实现DataModel的方法*************** */
/**************************************************** */
/**************************************************** */
/** ************以下为解析XML文件的方法*****************/
/**************************************************** */
protected void init() throwsTableDataException {
if (this.row_list != null)
return;
this.row_list = new ArrayList();
try {
SAXParserFactory f =SAXParserFactory.newInstance();
SAXParser parser =f.newSAXParser();
parser.parse(newFile(XMLParseDemoDataModel.this.filePath),
new DemoHandler());
} catch (Exception e) {
e.printStackTrace();
FRContext.getLogger().error(e.getMessage(), e);
}
}
/**
* 基本原理就是解析器在遍历文件时发现节点开始标记时，调用startElement方法读取节点内部内容时，调用characters方法
* 发现节点结束标记时，调用endElement
*/
private class DemoHandler extendsDefaultHandler {
private List levelList = newArrayList();
private Object[] values;
private int recordIndex = -1;
public void startElement(String uri,String localName, String qName,
Attributes attributes) throwsSAXException {
levelList.add(qName);
if (isRecordWrapTag()) {
values = newObject[XMLParseDemoDataModel.this.columns.length];
} else if (needReadRecord()) {
recordIndex =getColumnIndex(qName);
}
}
public void characters(char[] ch, intstart, int length)
throws SAXException {
if (recordIndex > -1) {
String text = new String(ch,start, length);
XMLColumnNameType4Demo type =XMLParseDemoDataModel.this.columns[recordIndex];
Object value = null;
if (type.getType() ==COLUMN_TYPE_STRING) {
value = text;
}
if (type.getType() ==COLUMN_TYPE_INTEGER) {
value = newInteger(text);
} else if (type.getType() ==COLUMN_TYPE_BOOLEAN) {
value = newBoolean(text);
}
values[recordIndex] = value;
}
}
public void endElement(String uri,String localName, String qName)
throws SAXException {
try {
if (isRecordWrapTag()) {
XMLParseDemoDataModel.this.row_list.add(values);
values = null;
} else if (needReadRecord()){
recordIndex = -1;
}
} finally {
levelList.remove(levelList.size() - 1);
}
}
private boolean isRecordWrapTag(){
if (levelList.size() ==XMLParseDemoDataModel.this.xPath.length
&& compareXPath()){
return true;
}
return false;
}
private boolean needReadRecord() {
if (levelList.size() ==(XMLParseDemoDataModel.this.xPath.length + 1)
&& compareXPath()){
return true;
}
return false;
}
private boolean compareXPath() {
String[] xPath =XMLParseDemoDataModel.this.xPath;
for (int i = 0; i <xPath.length; i++) {
if(!ComparatorUtils.equals(xPath[i], levelList.get(i))) {
return false;
}
}
return true;
}
private int getColumnIndex(StringcolumnName) {
XMLColumnNameType4Demo[] nts =XMLParseDemoDataModel.this.columns;
for (int i = 0; i < nts.length;i++) {
if(ComparatorUtils.equals(nts[i].getName(), columnName)) {
return i;
}
}
return -1;
}
}
}
