JXLS (Excel Import, Export tool)

JXLS (Excel Import, Export tool)

1 Introduction:

jxls is a simple, lightweight excel export library, defined in the excel template file output format and layout using specific markers. java excel in mature export tools pol, jxl, but they all use java code to export excel, and inconvenient coding efficiency is very low maintenance.

You can also use some of the tools are easy to implement export template. The tool is still maintained, and the country has done better easyPOI, the foreign is this JXLS.

Compare:

There are many complex project report (a large number of cells merge and cell styles), easyPOI processing time merged cells prone to damaging situation, poi code maintenance cost is high.

2: maven dependency:

<dependency>
    <groupId>org.jxls</groupId>
    <artifactId>jxls</artifactId>
    <version>2.4.6</version>
</dependency>
<dependency>
    <groupId>org.jxls</groupId>
    <artifactId>jxls-poi</artifactId>
    <version>1.0.12</version>
</dependency>
<dependency>
    <groupId>org.jxls</groupId>
    <artifactId>jxls-jexcel</artifactId>
    <version>1.0.6</version>
</dependency>

2: The following do first to achieve a simple export:

1: Create a model:

2: create a template with office xlsx

Here you can see some cell text annotation, office in annotate shortcut (Shit + F2) , annotate the class content here first no explanation, will be mentioned below

3：工具类JxlsUtils.java

public class JxlsUtils{
     
    private static final String TEMPLATE_PATH="jxls-template";
     
    public static void exportExcel(InputStream is, OutputStream os, Map<String, Object> model) throws IOException{
        Context context = new Context();
        if (model != null) {
            for (String key : model.keySet()) {
                context.putVar(key, model.get(key));
            }
        }
        JxlsHelper jxlsHelper = JxlsHelper.getInstance();
        Transformer transformer  = jxlsHelper.createTransformer(is, os);
        JexlExpressionEvaluator evaluator = (JexlExpressionEvaluator)transformer.getTransformationConfig().getExpressionEvaluator();
        Map<String, Object> funcs = new HashMap<String, Object>();
      //  funcs.put("utils", new JxlsUtils());    //添加自定义功能
      //  evaluator.getJexlEngine().setFunctions(funcs);
        jxlsHelper.processTemplate(context, transformer);
    }
 
    public static void exportExcel(File xls, File out, Map<String, Object> model) throws FileNotFoundException, IOException {
            exportExcel(new FileInputStream(xls), new FileOutputStream(out), model);
    }
     
    public static void exportExcel(String templateName, OutputStream os, Map<String, Object> model) throws FileNotFoundException, IOException {
        File template = getTemplate(templateName);
        if(template!=null){
            exportExcel(new FileInputStream(template), os, model);    
        }
    }
     
     
    //获取jxls模版文件
 
    public static File getTemplate(String name){
        String templatePath = JxlsUtils.class.getClassLoader().getResource(TEMPLATE_PATH).getPath();
        File template = new File(templatePath, name);
        if(template.exists()){
            return template;
        }
        return null;
    }    
     
    // 日期格式化
    public String dateFmt(Date date, String fmt) {
        if (date == null) {
            return "";
        }
        try {
            SimpleDateFormat dateFmt = new SimpleDateFormat(fmt);
            return dateFmt.format(date);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "";
    }
     
    // if判断
    public Object ifelse(boolean b, Object o1, Object o2) {
        return b ? o1 : o2;
    }
     
}

上面注释中的自定义功能可以先注释到，我们后面在讲

入口ObjectCollectionDemo.java

public class ObjectCollectionDemo {
    static Logger logger = LoggerFactory.getLogger(ObjectCollectionDemo.class);
     
    public static void main(String[] args) throws ParseException, IOException {
        logger.info("Running Object Collection demo");
         
        List<Employee> employees = generateSampleEmployeeData();
        OutputStream os = new FileOutputStream("target/object_collection_output.xls");
        Map<String , Object> model=new HashMap<String , Object>();
        model.put("employees", employees);
        model.put("nowdate", new Date());
        JxlsUtils.exportExcel("object_collection_template.xls", os, model);
        os.close();
    }
 
    public static List<Employee> generateSampleEmployeeData() throws ParseException {
        List<Employee> employees = new ArrayList<Employee>();
        SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MMM-dd", Locale.US);
        employees.add( new Employee("Elsa", dateFormat.parse("1970-Jul-10"), 1500, 0.15) );
        employees.add( new Employee("Oleg", dateFormat.parse("1973-Apr-30"), 2300, 0.25) );
        employees.add( new Employee("Neil", dateFormat.parse("1975-Oct-05"), 2500, 0.00) );
        employees.add( new Employee("Maria", dateFormat.parse("1978-Jan-07"), 1700, 0.15) );
        employees.add( new Employee("John", dateFormat.parse("1969-May-30"), 2800, 0.20) );
        return employees;
    }
}

生成效果：

好的，这样就很轻松的导出了是不是很简单

3：下面讲一下导出的细节，注意事项：

1：模板中的批注：

注意如果模板中对单元格加了批注，但是没有批注信息的话可能会报错：

1-1：bean属性标记

jxls使用 Apache JEXL表达式语言来解析定义在excel模板中的表达式。JEXL与JSTL相似，并对JSTL进行了扩展。eg：

${department.chief.age} //属性可以是无限深度

${utils:dateFmt(date,"yyyy-MM-dd")} //自定义工具函数

JXLS (Excel Import, Export tool)

1-2：XLS Area定义标记

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