java 常用的包
org.apache.commons.lang.StringUtils 常用方法
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.4</version>
</dependency>
示例：
import org.apache.commons.lang.StringUtils;
public class Test{
@SuppressWarnings({ "deprecation", "unused" })
public static void test(String[] args) {
/*************************判 空**********************************/
//判断是否Null 或者 "" 【不去空格】为空的标准是 str==null 或 str.length()==0
boolean isEmpty = StringUtils.isEmpty("");//true
boolean isEmpty1 = StringUtils.isEmpty(" ");//false
boolean isEmptyNull = StringUtils.isEmpty(null);//true
// 判断是否Null 或者 "" 【去空格】为空的标准是 str==null 或 str.length()==0
boolean isBlack = StringUtils.isBlank("");//true
boolean isBlack1 = StringUtils.isBlank(" ");//true
boolean isBlankNull = StringUtils.isBlank(null);//true
//找到2个字符串第一个出现不同的位置（1开始）
String difference = StringUtils.difference("s123", "s13");
System.out.println(difference);//3
//判断2个字符串是否相等
boolean equals = StringUtils.equals("s1", "s1");
System.out.println(equals);//true
// 不区分大小写判断两个字符串是都相等
boolean equalsIgnoreCase = StringUtils.equalsIgnoreCase("abc", "ABc");//true
System.out.println(equalsIgnoreCase);
//判断字符串里面是否含有特定字符串
boolean b2 = StringUtils.contains("asd", "as");
System.out.println(b2);//true
//把数组的元素用:进行拼接
String concatStr = StringUtils.join(new String[]{"dog", "cat", "monkey"},":");
System.out.println(concatStr);//dog:cat:monkey
//根据特定分隔符对字符串进行拆分
String[] split = StringUtils.split("apple|xiaomi|dell|lenovo", "|");
for (String s1 : split) {
System.out.print(s1 + "、");//apple、xiaomi、dell、lenovo、
}
System.out.println();
//所有单词首字母大写
String capitaliseAllWords = StringUtils.capitaliseAllWords("today i will go to china");
System.out.println(capitaliseAllWords);//Today I Will Go To China
//统计某个字符串在字符串出现的次数
int matchCount = StringUtils.countMatches("Happy Birthday to you", "o");
System.out.println(matchCount);//2
//必须要8位，不够的就拿0去字符串左边补
String leftPad = StringUtils.leftPad("54", 8, "0");
System.out.println(leftPad);//00000054
//必须要8位，不够的就拿0去字符串右边补
String rightPad = StringUtils.rightPad("54", 8, "0");
System.out.println(rightPad);//54000000
//判断字符串是否以特定字符串开头，区分大小写
boolean startsWith = StringUtils.startsWith("GoodMorning", "go");
System.out.println(startsWith);//false
//判断字符串是否以特定字符串结尾，区分大小写
boolean endsWith = StringUtils.endsWith("GoodMorning", "ing");
System.out.println(endsWith);//true
// 去空格
StringUtils.trim(" 222 ");//222
//将null和""转换为null
StringUtils.trimToNull("");//null
// 将null和""转换为""
StringUtils.trimToEmpty(null);//""
//当第一个字符串为null或者""时返回第二个参数
StringUtils.defaultIfEmpty(null, "sos");//sos
StringUtils.defaultIfEmpty("", "sos");//sos
StringUtils.defaultIfEmpty("111", "sos");//111
// 去除参数首尾和第二个参数相同的字符,如果第二个参数为null那就去除首尾的空格
StringUtils.strip("fsfsdf", "f");//sfsd
StringUtils.strip("fsfsdfa", "f");//sfsdfa
// 去除首部和第二个参数相同的字符,如果第二个参数为null那就去除首部的空格
StringUtils.stripStart("ddsuuud", "d");//suuud
// 去除尾部和第二个参数相同的字符,如果第二个参数为null那就去除尾部的空格
StringUtils.stripEnd("ddsuuud", "d");//ddsuuu
// 对数组整体去除首尾空格
//java
//c++
//python script
String[] strip = StringUtils.stripAll(new String[]{" java ", "c++ ", "python script"});
for(String aa : strip){
System.out.println(aa);
}
// 去掉数据中首尾和第二个参数一样的字符
//java
//hp
//ython script
String[] strip1 = StringUtils.stripAll(new String[]{" java ", "php ", "python script"},"p");
for(String aa : strip){
System.out.println(aa);
}
/**************************查找****************************/
// 查找第二个参数首次出现的位置(区分大小写)，如果第一个参数为null或者没有查找到时返回-1
StringUtils.indexOf("bbbb", "a");//-1
StringUtils.indexOf(null, "a");//-1
StringUtils.indexOf("aaaa", "a");//0
StringUtils.indexOf("aaaa", "A");//-1
// 查找第二个参数首次出现的位置(不区分大小写)，如果第一个参数为null或者没有查找到时返回-1
StringUtils.indexOf("bbbb", "A");//-1
StringUtils.indexOf(null, "A");//-1
StringUtils.indexOf("aaaa", "A");//0
}
public static void main(String[] args) {
System.out.println(StringUtils.indexOfIgnoreCase("abbb", "A"));
}
}
@Data（Lombok实现）
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.22</version>
<optional>true</optional>
</dependency>
示例
package com.example.lombok;
import lombok.Data;
@Data
public class Student {
private Integer id;
private String name;
private Integer gender;
private Integer classId;
}
可选配置 如果想要在 Maven 打包的时候，Lombok 不被打包，可使用如下配置。
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<excludes>
<exclude>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</exclude>
</excludes>
</configuration>
</plugin>
</plugins>
</build>
java利用POI解析Excel及图片
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>3.17</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>3.17</version>
</dependency>
package com.betawoo.admin.test.base;
import com.betawoo.admin.commons.utils.QiNiuUtils;
import org.apache.poi.POIXMLDocumentPart;
import org.apache.poi.hssf.usermodel.*;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.*;
import org.openxmlformats.schemas.drawingml.x2006.spreadsheetDrawing.CTMarker;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* Created by hgg on 2019/5/7.
*/
public class POIExcel {
public static void getDataFromExcel(String filePath) throws IOException
{
//判断是否为excel类型文件
if(!filePath.endsWith(".xls")&&!filePath.endsWith(".xlsx"))
{
System.out.println("文件不是excel类型");
}
FileInputStream fis =null;
Workbook wookbook = null;
Sheet sheet =null;
try
{
//获取一个绝对地址的流
fis = new FileInputStream(filePath);
/* 读取网络文件（比如七牛等云存储）
URL url = new URL(filePath);
BufferedInputStream fis = new BufferedInputStream(url.openStream());*/
}
catch(Exception e)
{
e.printStackTrace();
}
try
{
//2003版本的excel，用.xls结尾
wookbook = new HSSFWorkbook(fis);//得到工作簿
}
catch (Exception ex)
{
//ex.printStackTrace();
try
{
//2007版本的excel，用.xlsx结尾
fis = new FileInputStream(filePath);
wookbook = new XSSFWorkbook(fis);//得到工作簿
} catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
Map<String, PictureData> maplist=null;
sheet = wookbook.getSheetAt(0);
// 判断用07还是03的方法获取图片
if (filePath.endsWith(".xls")) {
maplist = getPictures1((HSSFSheet) sheet);
} else if(filePath.endsWith(".xlsx")){
maplist = getPictures2((XSSFSheet) sheet);
}
try {
printImg(maplist);
} catch (Exception e) {
e.printStackTrace();
}finally {
//释放map
if (maplist != null){
maplist = null;
}
}
//得到一个工作表
//获得表头
Row rowHead = sheet.getRow(0);
//获得数据的总行数
int totalRowNum = sheet.getLastRowNum();
//要获得属性
String proName="";
String space="";
String size="";
String brand="";
String unit="";
Integer num=null;
Double unitPrice=null;
Double total=null;
String material="";
String remark="";
String pic="";
//获得所有数据
System.out.println("产品名称\t\t空间\t\t规格/尺寸\t\t品牌\t\t单位\t\t数量\t\t单价\t\t金额\t\t材质\t\t备注");
for(int i = 1 ; i < totalRowNum ; i++)
{
//获得第i行对象
Row row = sheet.getRow(i);
//空间位置(为空则停止解析)
Cell cell = row.getCell(0);
if (cell == null){
break;
}
cell.setCellType(CellType.STRING);
space =cell.getStringCellValue().toString();
if (StringUtils.isBlank(space)){
break;
}
//产品名称
cell = row.getCell(1);
if (cell != null){
cell.setCellType(CellType.STRING);
proName = cell.getStringCellValue();
}
//规格/尺寸
cell = row.getCell(3);
if (cell != null){
cell.setCellType(CellType.STRING);
size =cell.getStringCellValue()+"";
}
//品牌
cell = row.getCell(4);
if (cell != null){
cell.setCellType(CellType.STRING);
brand =cell.getStringCellValue()+"";
}
//单位
cell = row.getCell(5);
if (cell != null){
cell.setCellType(CellType.STRING);
unit =cell.getStringCellValue()+"";
}
//数量
cell = row.getCell(6);
if (cell != null){
num =(int)cell.getNumericCellValue();
}
//单价
cell = row.getCell(7);
if (cell != null){
unitPrice =cell.getNumericCellValue();
}
//金额
cell = row.getCell(8);
if (cell != null){
total =cell.getNumericCellValue();
}
//材质
cell = row.getCell(9);
if (cell != null){
cell.setCellType(CellType.STRING);
material =cell.getStringCellValue()+"";
}
//备注
cell = row.getCell(10);
if (cell != null){
cell.setCellType(CellType.STRING);
remark =cell.getStringCellValue()+"";
}
System.out.println(proName+"\t\t"+space+"\t\t"+size+"\t\t"+brand+"\t\t"+unit+"\t\t"+num+"\t\t"
+unitPrice+"\t\t"+total+"\t\t"+material+"\t\t"+remark);
}
for (Map.Entry<String, PictureData> entry : maplist.entrySet()) {
System.out.println("Key = " + entry.getKey() + ", Value = " + entry.getValue());
}
//使用完成关闭
wookbook.close();
if (fis != null){
fis.close();
}
}
/**
* 获取图片和位置 (xls)
* @param sheet
* @return
* @throws IOException
*/
public static Map<String, PictureData> getPictures1 (HSSFSheet sheet) throws IOException {
Map<String, PictureData> map = new HashMap<String, PictureData>();
List<HSSFShape> list = sheet.getDrawingPatriarch().getChildren();
for (HSSFShape shape : list) {
if (shape instanceof HSSFPicture) {
HSSFPicture picture = (HSSFPicture) shape;
HSSFClientAnchor cAnchor = (HSSFClientAnchor) picture.getAnchor();
PictureData pdata = picture.getPictureData();
String key = cAnchor.getRow1() + "-" + cAnchor.getCol1(); // 行号-列号
map.put(key, pdata);
}
}
return map;
}
/**
* 获取图片和位置 (xlsx)
* @param sheet
* @return
* @throws IOException
*/
public static Map<String, PictureData> getPictures2 (XSSFSheet sheet) throws IOException {
Map<String, PictureData> map = new HashMap<String, PictureData>();
List<POIXMLDocumentPart> list = sheet.getRelations();
for (POIXMLDocumentPart part : list) {
if (part instanceof XSSFDrawing) {
XSSFDrawing drawing = (XSSFDrawing) part;
List<XSSFShape> shapes = drawing.getShapes();
for (XSSFShape shape : shapes) {
XSSFPicture picture = (XSSFPicture) shape;
XSSFClientAnchor anchor = picture.getPreferredSize();
CTMarker marker = anchor.getFrom();
String key = marker.getRow() + "-" + marker.getCol();
map.put(key, picture.getPictureData());
}
}
}
return map;
}
//图片写出
public static void printImg(Map<String, PictureData> sheetList) throws Exception {
Object key[] = sheetList.keySet().toArray();
String filePath = "";
for (int i = 0; i < sheetList.size(); i++) {
// 获取图片流
PictureData pic = sheetList.get(key[i]);
// 获取图片索引
String picName = key[i].toString();
// 获取图片格式
String ext = pic.suggestFileExtension();
byte[] data = pic.getData();
//文件上传七牛
// QiNiuUtils.uploadOneObject(data,"111_"+picName + "." + ext);
//图片保存路径
filePath = "D:\\img\\pic" + picName + "." + ext;
System.out.println(filePath);
FileOutputStream out = new FileOutputStream(filePath);
out.write(data);
out.close();
}
}
public static void main(String[] args) throws Exception {
getDataFromExcel("D:"+ File.separator +"test.xlsx");
}
}
java csv文件读取包
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-csv</artifactId>
<version>1.8</version> <!-- 请检查是否有更新的版本 -->
</dependency>
示例
在Java中，可以使用不同的库来读取CSV文件，其中最常用的是Apache Commons CSV和OpenCSV。
下面是使用Apache Commons CSV读取CSV文件的示例代码：
java
import org.apache.commons.csv.*;
import java.io.FileReader;
import java.io.IOException;
import java.util.List;
public class CSVReader {
public static void main(String[] args) {
try {
FileReader reader = new FileReader("data.csv");
Iterable<CSVRecord> records = CSVFormat.DEFAULT.withFirstRecordAsHeader().parse(reader);
for (CSVRecord record : records) {
String name = record.get("Name");
int age = Integer.parseInt(record.get("Age"));
System.out.println("Name: " + name + ", Age: " + age);
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
// 例假设CSV文件的第一行是标题行，其中包含“Name”和“Age”列名。在循环中，我们使用record.get()方法获取每个列的值，并使用System.out.println()将其打印到控制台。
// 想使用OpenCSV库，可以使用以下示例代码：
java
import com.opencsv.CSVReader;
import java.io.FileReader;
import java.io.IOException;
public class CSVReader {
public static void main(String[] args) {
try {
CSVReader reader = new CSVReader(new FileReader("data.csv"));
String[] nextLine;
while ((nextLine = reader.readNext()) != null) {
String name = nextLine[0];
int age = Integer.parseInt(nextLine[1]);
System.out.println("Name: " + name + ", Age: " + age);
}
} catch (IOException e) {
e.printStackTrace();
} catch (NumberFormatException e) {
e.printStackTrace();
}
}
}
// 例使用CSVReader类读取CSV文件，并使用readNext()方法逐行读取数据。注意，我们假设CSV文件中的第一列是名称，第二列是年龄。
