Java读取Excel文件的方法

在应用程序中经常需要读取Excel文件中的信息，在此将解析Excel文件的代码贴出，供需要的参考：

       Excel2003之前与Excel2007之后的文件组织方式，因此读取代码也不尽相同。

1. 读取Excel2003文件，Excel2003文件最大行数为65536行，利用HSSFWorkbook类可以完成：

     

public class XLSReader {
private List<String> lines = new ArrayList<String>();

private List<String> titles = new ArrayList<String>();

public void readFile(String fileNames) throws FileNotFoundException, IOException{

Workbook wb = new HSSFWorkbook(new FileInputStream(fileNames));
Sheet readsheet = wb.getSheetAt(0);
Iterator<Row> iter = readsheet.rowIterator();

//获取表头信息
if(iter.hasNext()){
titles.clear();
Row row = iter.next();
int colNum = row.getPhysicalNumberOfCells();
for(int i=0; i<colNum; i++){
Cell cell = row.getCell(i);
String value = getCellValue(cell);
titles.add(value);
}
}

while(iter.hasNext()){
Row row = iter.next();
int colNum = row.getPhysicalNumberOfCells();

lines.clear();
for(int i=0; i<colNum; i++){
Cell cell = row.getCell(i);
String value = getCellValue(cell);
lines.add(value);
}
}
}

public String getCellValue(Cell cell) {

if(null==cell){
return "";
}

switch(cell.getCellType()){

case Cell.CELL_TYPE_NUMERIC:
return String.valueOf(cell.getNumericCellValue());

case Cell.CELL_TYPE_STRING:
return cell.getStringCellValue();

case Cell.CELL_TYPE_FORMULA:
return cell.getCellFormula();

case Cell.CELL_TYPE_BOOLEAN:
return cell.getBooleanCellValue()==true ? "true" : "false";

case Cell.CELL_TYPE_ERROR:
try {
return new String(new byte[]{cell.getErrorCellValue()}, "UTF-8");
} catch (UnsupportedEncodingException e) {
return "";
}

case Cell.CELL_TYPE_BLANK:
return "";

default:
return cell.toString();
}
}

public static void main(String[] args) throws Exception{

XLSReader reader = new XLSReader();
reader.readFile("C:\\Users\\Administrator\\Desktop\\测试.xls");
}
}

2  读取Excel2007文件，由于Excel2007文件与Excel2003文件组织方式不同，当文件较小时，将上述代码的HSSFWorkbook换成XSSFWorkbook即可，但这样方式是将文件全部内容加载至内存中，当文件较大时，例如10万以上时，很容易造成内存溢出，Excel2007基于XML标准编写，基于这个思路利用SAX方式读取Excel2007文件:

public class SAXReader {

private List<String> titlelist = new ArrayList<String>();

private List<String> lines = new ArrayList<String>();

public List<String> getTitle(){
return this.titlelist;
}

public void processFirstSheet(String filename) throws Exception {
OPCPackage pkg = OPCPackage.open(filename);
XSSFReader r = new XSSFReader(pkg);
SharedStringsTable sst = r.getSharedStringsTable();
XMLReader parser = fetchSheetParser(sst);

InputStream sheet2 = r.getSheet("rId1");
InputSource sheetSource = new InputSource(sheet2);
//解析xlsx文件转换的xml文档
parser.parse(sheetSource);
sheet2.close();
}

public XMLReader fetchSheetParser(SharedStringsTable sst) throws SAXException {
XMLReader parser =  XMLReaderFactory.createXMLReader("org.apache.xerces.parsers.SAXParser");
ContentHandler handler = new SheetHandler(sst);
parser.setContentHandler(handler);
return parser;
}

/**
* 自定义解析处理器
* See org.xml.sax.helpers.DefaultHandler javadocs
*/
private class SheetHandler extends DefaultHandler {

private SharedStringsTable sst;
private String lastContents;
private boolean nextIsString;

private int curRow = 0;
private int curCol = 0;

//定义前一个元素和当前元素的位置，用来计算其中空的单元格数量，如A6和A8等
private String preRef = null, ref = null;

private SheetHandler(SharedStringsTable sst) {
this.sst = sst;
}

/**
* 解析一个element的开始时触发事件
*/
public void startElement(String uri, String localName, String name,  Attributes attributes) throws SAXException {

if(name.equals("c")) {
//前一个单元格的位置
if(preRef == null){
preRef = attributes.getValue("r");
}else{
preRef = ref;
}
//当前单元格的位置
ref = attributes.getValue("r");

// Figure out if the value is an index in the SST
String cellType = attributes.getValue("t");
if(cellType != null && cellType.equals("s")) {
nextIsString = true;
} else {
nextIsString = false;
}
}
lastContents = "";
}

/**
* 解析一个element元素结束时触发事件
*/
public void endElement(String uri, String localName, String name) throws SAXException {

if(nextIsString) {
int i
a122
dx = Integer.parseInt(lastContents);
lastContents = new XSSFRichTextString(sst.getEntryAt(idx)).toString();
nextIsString = false;
}

//获取表头信息
if (name.equals("v") && curRow==0) {
String value = lastContents.trim();
titlelist.add(curCol, value);
curCol++;
}else {
if (name.equals("row")) {
curCol=0;
curRow++;
}

if(curCol==0){
lines.clear();
}

if(name.equals("c") && curRow>0){
lines.add(lastContents.trim());
curCol++;
}
}
}

/**
* 获取element的文本数据
*/
public void characters(char[] ch, int start, int length) {
lastContents += new String(ch, start, length);
}

}

public static void main(String[] args) throws Exception {

SAXReader reader = new SAXReader();
reader.processFirstSheet("C:\\Users\\Administrator\\Desktop\\测试.xlsx");
reader.loadData();
}

}