java杂记

字符串截取

字符串路径截取

  filename="2017\11\01\050000001\7b3d73a2e080c2722e1fb6e71be2f0be_aaa2.doc"
  
  //截取最后一个反斜杠后面的内容，即：7b3d73a2e080c2722e1fb6e71be2f0be_aaa2.doc
   String filenameStr =  filename.substring(filename.lastIndexOf("\\")+1);
   
   //截取开头到最后一个反斜杠之间的内容，即：2017\11\01\050000001\
   String filePathStr =  filename.substring(0,filename.lastIndexOf("\\")+1);

URL转码解码

   //转码
   String filenameStr2 = java.net.URLEncoder.encode(filenameStr, "utf-8");
   
   //解码
   java.net.URLDecoder.decode(str, ENCODE);
   
   参考网址:
   http://www.cnblogs.com/haha12/p/4344992.html

重新拼接

   //重新拼接
   filename = filePathStr+filenameStr2;

反斜杠转正斜杠

   //将反斜杠替换为正斜杠
   filename.replace("\\", "/"))

字符串年月日时分秒毫秒

   //年月日时分秒毫秒
  java.text.SimpleDateFormat date = new java.text.SimpleDateFormat("yyyyMMddHHmmssSS");
  String currentTimeMillis = date.format(new Date(System.currentTimeMillis()));

截图文件后缀重新拼接

  //fileName="fjsdfidjfi.swf"
  String suffix = fileName.substring(fileName.lastIndexOf("."));
  //拼接得到结果：20171102103140271.swf
  String newFileName = currentTimeMillis + suffix;

Date转时间戳

  import java.sql.Timestamp;
  import java.text.SimpleDateFormat;
  import java.util.Calendar;
  import java.util.Date;
  
  public class Test {
      public static void main(String[] args) {
          Timestamp timestamp = new Timestamp((new Date()).getTime());
          //System.out.println("wre:"+timestamp);
  
          String s = timestamp.toString();
          Timestamp ts = Timestamp.valueOf(s);
          Calendar c = Calendar.getInstance();
          SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd/HH:mm:ss");//hh:12小时制，HH小时制度
          System.out.println(sdf.format(c.getTime()));
  
      }
  }

StringUtils截取字符串

截取 }, 之后的字符串，不包含 },

  String str4 = StringUtils.substringAfter(jsonArray.toString(),"},");

依赖包

  import org.apache.commons.lang3.StringUtils;

依赖包maven配置

  <!-- commons-lang3 -->
  <dependency>
      <groupId>org.apache.commons</groupId>
      <artifactId>commons-lang3</artifactId>
      <version>3.1</version>
  </dependency>

mybatis参数映射

mybatis参数映射
and h.regist_status = #{hallRegistration.statusLeave,jdbcType=VARCHAR}

字符串替换正则

字符串替换正则
str.replaceAll(“ {2,}”, “ “)

jar重新编译

重新编译命令

  1.将原先demo.jar解压
  2.cd进入解压后的demo文件夹
  3.执行重新编译命令（命令中的demo.jar是打包后的名字）
  jar cfm demo.jar ./META-INF/MANIFEST.MF ./

java图片压缩

 //图片压缩
    File file = new File(annex.getAnnexPath());
    //判断文件时候大于10M
    if (file.exists() && (file.length() / 1024f / 1024f) > 10) {
    try {
        System.out.println("文件大小：" + file.length() / 1024f / 1024f);
        
        FileInputStream fileInputStream = new FileInputStream(file);
        BufferedImage originalImage = ImageIO.read(fileInputStream);
        Thumbnails.of(originalImage)
                .scale(1f) //图片大小（长宽）压缩比例 从0-1，1表示原图
                .outputQuality(0.8) //图片质量压缩比例 从0-1，越接近1质量越好
                .toFile(annex.getAnnexPath());
    } catch (Exception e) {
        log.error("图片压缩失败：" + e.getMessage() + annex.getAnnexPath());
    }
}

//依赖包
<dependency>
    <groupId>net.coobird</groupId>
    <artifactId>thumbnailator</artifactId>
    <version>0.4.14</version>
</dependency>

uxawseny

java杂记

字符串截取

Date转时间戳

StringUtils截取字符串

mybatis参数映射

字符串替换正则

jar重新编译

java图片压缩

待续…