Java使用excel工具类导出对象功能示例

package com.gcloud.common;import org.apache.poi.ss.usermodel.Cell;import org.apache.poi.ss.usermodel.Row;import org.apache.poi.ss.usermodel.Sheet;import org.apache.poi.xssf.streaming.SXSSFSheet;import org.apache.poi.xssf.streaming.SXSSFWorkbook;import java.io.FileOutputStream;import java.lang.reflect.Method;import java.util.ArrayList;import java.util.List;public class ExcelExportUtil {  // 1、定义工作表  private SXSSFWorkbook workbook;  // 2、定义sheet  private Sheet sheet;  // 3、定义保存在内存中的数量,-1表示手动控制  private int flushRows;    private int rowNum;    private int colNum;    private String filePath;    private String fileWebPath;    private String filePrefix;    private String fileAllPath;    private List<String> fieldNames;    private List<String> fieldCodes;  //---构造方法-----------------------------------------  public ExcelExportUtil() {  }  public ExcelExportUtil(SXSSFWorkbook workbook) {    this.workbook = workbook;  }  public static ExcelExportUtil start(String filePath, String fileWebPath, String filePrefix, List<String> fieldNames, List<String> fieldCodes, int flushRows) throws Exception {    ExcelExportUtil excelExportUtil = new ExcelExportUtil();    excelExportUtil.setFilePath(filePath);    excelExportUtil.setFileWebPath(fileWebPath);    excelExportUtil.setFilePrefix(filePrefix);    excelExportUtil.setFieldNames(fieldNames);    excelExportUtil.setFieldCodes(fieldCodes);    //设置输出行数    excelExportUtil.setWorkbook(new SXSSFWorkbook(flushRows));    //设置sheet    excelExportUtil.setSheet(excelExportUtil.getWorkbook().createSheet());    excelExportUtil.writeTitles();    return excelExportUtil;  }    public void writeTitles() throws Exception {    rowNum = 0;    colNum = fieldNames.size();    //创建行    Row row = sheet.createRow(rowNum);    //在每列第一行输出    for (int i = 0; i < colNum; i++) {      Cell cell = row.createCell(i);      cell.setCellValue(fieldNames.get(i));    }  }    public void writeDatas(List datalist) throws Exception {    for (int i = 0; i < datalist.size(); i++) {      rowNum++;      //不断创建行      Row row = sheet.createRow(rowNum);      for (int j = 0; j < fieldCodes.size(); j++) {        Object obj = datalist.get(j);        //获得get方法返回的值        Object value = invokeMethod(obj, fieldCodes.get(j), new Object[]{});        Cell cell = row.createCell(j);        cell.setCellValue(value != null ? value.toString() : "");      }    }  }    private Object invokeMethod(Object owner, String fieldname, Object[] args) throws Exception {    String methodName = "get" + fieldname.substring(0,1).toUpperCase() + fieldname.substring(1);    Class ownerClass = owner.getClass();    Class[] argsClass = new Class[args.length];    for (int i = 0, j = argsClass.length ; i <j ; i++) {      argsClass[i] = args[i].getClass();    }    Method method = ownerClass.getMethod(methodName, argsClass);    return method.invoke(owner, args);  }    public void writeDatasByStr(List<String> datalist) throws Exception {    rowNum++;    Row row = sheet.createRow(rowNum);    int dataSize = datalist.size();    for (int i = 0; i < colNum; i++) {      Cell cell = row.createCell(i);      cell.setCellValue(dataSize > i ? datalist.get(i) : "");    }  }    public void flush(int flushNum) throws Exception{    ((SXSSFSheet)sheet).flushRows(flushNum);  }    public String exportFile() throws Exception{    String fileName = filePrefix + "_" + DateUtil.getCurrentTimeFileName() + ".xlsx";    FileOutputStream fos = new FileOutputStream(filePath + fileName);    workbook.write(fos);    fos.close();    setFileAllPath(fileWebPath + fileName);    return fileWebPath + fileName;  }    public ExcelExportUtil excelExport(String field,String path,String webpath,String filePrefix,List datas,int flushRows) throws Exception{    //导出字段代码和名称    String[] fieldArr = field.split(",");    //获取导出字段名称    List<String> fieldNames = new ArrayList<String>();    //获取导出字段代码    List<String> fieldCodes = new ArrayList<String>();    for (int i = 0; i < fieldArr.length; i++) {      String names = fieldArr[i];      String[] nameArr = names.split("#");      fieldNames.add(nameArr[1]);      fieldCodes.add(nameArr[0]);    }    //开导出    ExcelExportUtil exportUtil = ExcelExportUtil.start(path, webpath,filePrefix, fieldNames,fieldCodes, flushRows);    //导数据    exportUtil.writeDatas(datas);    exportUtil.exportFile();    return exportUtil;  }  public static void main(String[] args) {    //使用方法，调用    //excelExport  }  //----get set-------------------------------------------------  public SXSSFWorkbook getWorkbook() {    return workbook;  }  public void setWorkbook(SXSSFWorkbook workbook) {    this.workbook = workbook;  }  public Sheet getSheet() {    return sheet;  }  public void setSheet(Sheet sheet) {    this.sheet = sheet;  }  public int getFlushRows() {    return flushRows;  }  public void setFlushRows(int flushRows) {    this.flushRows = flushRows;  }  public int getRowNum() {    return rowNum;  }  public void setRowNum(int rowNum) {    this.rowNum = rowNum;  }  public int getColNum() {    return colNum;  }  public void setColNum(int colNum) {    this.colNum = colNum;  }  public String getFilePath() {    return filePath;  }  public void setFilePath(String filePath) {    this.filePath = filePath;  }  public String getFileWebPath() {    return fileWebPath;  }  public void setFileWebPath(String fileWebPath) {    this.fileWebPath = fileWebPath;  }  public String getFilePrefix() {    return filePrefix;  }  public void setFilePrefix(String filePrefix) {    this.filePrefix = filePrefix;  }  public String getFileAllPath() {    return fileAllPath;  }  public void setFileAllPath(String fileAllPath) {    this.fileAllPath = fileAllPath;  }  public List<String> getFieldNames() {    return fieldNames;  }  public void setFieldNames(List<String> fieldNames) {    this.fieldNames = fieldNames;  }  public List<String> getFieldCodes() {    return fieldCodes;  }  public void setFieldCodes(List<String> fieldCodes) {    this.fieldCodes = fieldCodes;  }}