应用Java泛型和反射导出CSV文件的方法

本文实例讲述了应用Java泛型和反射导出CSV文件的方法。分享给大家供大家参考。具体如下：

项目中有需求要把数据导出为CSV文件，因为不同的类有不同的属性，为了代码简单，应用Java的泛型和反射，写了一个函数，完成导出功能。

复制代码代码如下:

public <T> void saveFile(List<T> list, String outFile) throws IOException {
        if (list == null || list.isEmpty()) {
            return;
        }
        if (StringUtils.isEmpty(outFile)) {
            throw new IllegalArgumentException("outfile is null");
        }
        boolean isFirst = true;
        BufferedWriter out = null;
        try {
            out = new BufferedWriter(new FileWriter(outFile));
            for (T t : list) {
                StringBuilder sb1 = new StringBuilder();
                StringBuilder sb2 = new StringBuilder();
                Class clazz = (Class) t.getClass();
                Field[] fs = clazz.getDeclaredFields();
                for (int i = 0; i < fs.length; i++) {
                    Field f = fs[i];
                    f.setAccessible(true);
                    try {
                        if (isFirst) {
                            sb1.append(f.getName());
                            sb1.append(",");
                        }
                        Object val = f.get(t);
                        if (val == null) {
                            sb2.append("");
                        } else {
                            sb2.append(val.toString());
                        }
                        sb2.append(",");
                    } catch (IllegalArgumentException | IllegalAccessException e) {
                        e.printStackTrace();
                    }
                }
                if (isFirst) {
                    out.write(sb1.toString());
                    isFirst = false;
                    out.newLine();
                }
                out.write(sb2.toString());
                out.newLine();
            }
        } catch (IOException e1) {
            throw e1;
        } finally {
            try {
                if (out != null) {
                    out.close();
                }
            } catch (IOException e2) {
                throw e2;
            }
        }
}

 

希望本文所述对大家的Java程序设计有所帮助。