依赖：
<!-- excel 导出 --> <dependency> <groupId>org.apache.poi</groupId> <artifactId>poi</artifactId> <version>RELEASE</version> </dependency> <dependency> <groupId>org.apache.poi</groupId> <artifactId>poi-ooxml</artifactId> <version>RELEASE</version> </dependency>
核心类：
package com.cy.common.utils;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
/**
* excel 工具
*
* @author Admin
*
*/
public class ExcelUtils {
@SuppressWarnings("resource")
public static <T> void httpDownload(HttpServletResponse response, String fileName, List<String> fields, List<T> data) throws IOException {
HSSFWorkbook workbook = new HSSFWorkbook();
HSSFSheet sheet = workbook.createSheet("sheet1");
if( data == null ) {
data = new ArrayList<T>();
}
for(int i=0;i<data.size();i++) {
Object rowData = data.get(i);
if( rowData == null ) {
continue;
}
Map<String, String> map = BeanUtils.toFormatMap(rowData);
HSSFRow row = sheet.createRow(i);
for( int j=0;j<fields.size();j++ ) {
HSSFCell cell = row.createCell(j);
String value = map.get( fields.get( j ) );
cell.setCellValue( value==null?"":value );
}
}
response.setHeader("Content-Disposition","attachment;filename=" + new String( fileName.getBytes(), "iso-8859-1") + ".xlsx");
response.setContentType("application/vnd.ms-excel;fileName=");
ServletOutputStream out = response.getOutputStream();
workbook.write(out);
}
@SuppressWarnings("resource")
public static <T> void httpDownload(HttpServletResponse response, String fileName, List<String> titles , List<String> fields, List<T> data) throws IOException {
HSSFWorkbook workbook = new HSSFWorkbook();
HSSFSheet sheet = workbook.createSheet("sheet1");
if( data == null ) {
data = new ArrayList<T>();
}
HSSFRow titleRow = sheet.createRow(0);
for( int j=0;j<titles.size();j++ ) {
HSSFCell cell = titleRow.createCell(j);
cell.setCellValue( titles.get(j) );
}
for(int i=1;i<data.size();i++) {
Object rowData = data.get(i);
if( rowData == null ) {
continue;
}
Map<String, String> map = BeanUtils.toFormatMap(rowData);
HSSFRow row = sheet.createRow(i);
for( int j=0;j<fields.size();j++ ) {
HSSFCell cell = row.createCell(j);
String value = map.get( fields.get( j ) );
cell.setCellValue( value==null?"":value );
}
}
response.setHeader("Content-Disposition","attachment;filename=" + new String( fileName.getBytes(), "iso-8859-1") + ".xlsx");
response.setContentType("application/vnd.ms-excel;fileName=");
ServletOutputStream out = response.getOutputStream();
workbook.write(out);
}
}
使用到的 工具类：
package com.cy.common.utils;
import java.io.File;
import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.fasterxml.jackson.databind.annotation.JsonSerialize;
import com.github.pagehelper.Page;
/**
* bean的工具类
* @author ZHANGYUKUN
*
*/
public class BeanUtils {
private static Logger logger = LoggerFactory.getLogger(BeanUtils.class);
/**
* 复制一个对象到另一个对象，忽略null值字段
*
*
* @param source
* @param target
* @param ignoreNull
*/
public static void copyProperties(Object source, Object target, Boolean ignoreNull) {
if( target == null ) {
return ;
}
if( source == null ) {
return ;
}
if (!ignoreNull) {
org.springframework.beans.BeanUtils.copyProperties(source, target);
} else {
String[] ignoreFiled = getNullField(source);
org.springframework.beans.BeanUtils.copyProperties(source, target, ignoreFiled);
}
}
public static void copyProperties(Object source, Object target) {
copyProperties( source ,target ,false );
}
/**
* 创建并复制一个对象
* @return
* @throws InstantiationException
* @throws IllegalAccessException
*/
public static <T> T copyNew(Object source, Class<T> targetCls) {
if( source == null ) {
return null;
}
T rt;
try {
rt = targetCls.getDeclaredConstructor().newInstance();
} catch (Exception e) {
e.printStackTrace();
return null;
}
org.springframework.beans.BeanUtils.copyProperties(source, rt);
return rt;
}
/**
* 复制信息到outList
*
* @param list
* @param cls
* @return
*/
@SuppressWarnings("unchecked")
public static <T> List<T> copyToOutList(List<?> list, Class<T> cls) {
if( list == null ) {
return null;
}
List<T> rtList = null;
try {
rtList = list.getClass().getDeclaredConstructor().newInstance();
if( list instanceof Page ) {
Page<Object> pageList = (Page<Object>) rtList;
Page<Object> temp = (Page<Object>) list;
pageList.setPageNum( temp.getPageNum() );
pageList.setPageSize( temp.getPageSize() );
pageList.setPages( temp.getPages() );
pageList.setTotal( temp.getTotal() );
}
for( Object item : list ) {
T rtItem = cls.getDeclaredConstructor().newInstance();
BeanUtils.copyProperties( item , rtItem , false );
rtList.add( rtItem );
}
} catch (Exception e) {
e.printStackTrace();
}
return rtList;
}
/**
*复制分页信息
*
* @param source
* @param target
*/
@SuppressWarnings("unused")
private static void copyPageList(Object source, Object target ) {
String[] ignoreFiled = new String[] {"result"};
org.springframework.beans.BeanUtils.copyProperties(source, target, ignoreFiled);
}
/**
* 得到 值为null 的字段 （只找当前类，没找父类，因为我们的实体暂时没有继承关系）
*
* @param source
* @return
*/
public static String[] getNullField(Object source) {
List<String> fieldList = new ArrayList<>();
Field[] fields = source.getClass().getDeclaredFields();
for (Field field : fields) {
field.setAccessible(true);
try {
if (field.get(source) == null) {
fieldList.add(field.getName());
}
} catch (IllegalArgumentException | IllegalAccessException e) {
e.printStackTrace();
}
}
return fieldList.toArray(new String[] {});
}
/**
* 得到定义的所有字段（返回数组）
*
* @return
*/
public static String[] getDeclareField(Class<?> cls) {
return getDeclareFieldAsList(cls).toArray(new String[] {});
}
/**
* 得到定义的所有字段(返回list)
*
* @return
*/
public static List<String> getDeclareFieldAsList(Class<?> cls) {
List<String> fieldList = new ArrayList<>();
Field[] fields = cls.getDeclaredFields();
for (Field field : fields) {
fieldList.add( field.getName() );
}
return fieldList;
}
/**
* 检查 in对象(如果有必填字段name就会抛出异常)
*/
@SuppressWarnings("unchecked")
public static void checkInObjectRequired(Object inObj) {
Class<?> cls = inObj.getClass();
Field[] fields = cls.getDeclaredFields();
for (Field field : fields) {
Class<? extends Annotation> apiParamCls;
try {
apiParamCls = (Class<? extends Annotation>) Class.forName("io.swagger.annotations.ApiModelProperty");
} catch (ClassNotFoundException e) {
return ;
}
if (field.isAnnotationPresent( apiParamCls )) {
Annotation apiParam = field.getAnnotation( apiParamCls );
Object fieldValue = null;
Boolean requiredValue = false;
String allowableValues = null;
try {
field.setAccessible(true);
// 取值-是否必填
Method method = apiParamCls.getMethod("required");
requiredValue = (Boolean) method.invoke( apiParam );
// 取值-限制条件
method = apiParamCls.getMethod("allowableValues");
allowableValues = (String) method.invoke( apiParam );
// 取值-field的值
fieldValue = field.get(inObj);
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
/**
* 检查某个out对象
*
* @param cls
*/
public static void checkOutObject(Class<?> cls) {
Field[] fields = cls.getDeclaredFields();
for (Field field : fields) {
Class<?> fieldCls = field.getType();
if (fieldCls.equals(Long.class) || fieldCls.equals(long.class)) {
if (!field.getName().equals("serialVersionUID")) {
if (!field.isAnnotationPresent(JsonSerialize.class)) {
if( logger.isWarnEnabled() ) {
logger.warn("类" + cls +"字段" +field.getName() +"是Long，写成向前端放回的时候可能丢失精度，你大概可以在字段上面加上：@JsonSerialize(using = LongJsonSerializer.class) 来改善这个问题 " );
}
}
}
}
}
}
/**
* 检查这个类和他的同包下面的out对象
* @param clss
*/
public static void checkOutObjectAll( Class<?> clss ) {
File file =new File( clss.getResource("").getPath() ) ;
if (file.exists() && file.isDirectory()) {
for (File itemFile : file.listFiles()) {
if (itemFile.isDirectory() || !itemFile.getName().endsWith(".class")) {
continue;
}
String className = ClassUtils.getSimpleClassName(itemFile.getName());
try {
Class<?> cls = BeanUtils.class.getClassLoader().loadClass( clss.getPackage().getName()+"." + className);
checkOutObject( cls );
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
}
}
/**
* 得到枚举数组的 names
* @param enums
* @return 枚举的names
*/
public static List<String> enumArraysNames( Enum<?>[] enums ) {
List<String> names = new ArrayList<>();
for( Enum<?> em : enums ) {
names.add( em.name() );
}
return names;
}
/**
* 对象 装换成 有格式的 Map( 打印，导出专用 )
* @param data
* @return
*/
public static Map<String, String> toFormatMap(Object obj) {
Map<String, String> map = new HashMap<String, String>();
Method[] methods = obj.getClass().getMethods();
for (Method method : methods) {
try {
int mod = method.getModifiers();
if (Modifier.isStatic(mod) || Modifier.isFinal(mod)) {
continue;
}
if (!method.getName().startsWith("get")) {
continue;
}
Object value = method.invoke(obj);
if (value != null) {
String name = method.getName().substring(3, 4).toLowerCase() + method.getName().substring(4);
if( value instanceof Enum && value.getClass().getPackage().getName().contains("com.cy.order") ) {
Method emM = value.getClass().getMethod("getValue");
map.put(name, emM.invoke( value )+"" );
}else if( value instanceof Date ){
map.put(name, DateUtils.format( (Date)value , 3) );
}else if( method.getName().contains("Amount") ){
map.put(name, MoneyJsonSerializer.format( (Long)value) );
}else {
map.put(name, value.toString());
}
}
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
} catch (NoSuchMethodException e) {
e.printStackTrace();
} catch (SecurityException e) {
e.printStackTrace();
}
}
return map;
}
}
使用例子:
Result<List<OrderStatusView>> data = listPayOrder(in); List<String> titles = Arrays.asList( "订单号","病人名","病人Id","交易类型","交易金额","支付方式","交易单号","交易时间","交易状态","平台商户"); List<String> fileNames = Arrays.asList( "id","name","cardNum","tradeType","amount","payType","payOrderId","payOrderDate","ph","merchantName"); ExcelUtils.httpDownload(response, "查询支付单列表",titles, fileNames , data.getData());
效果图：
