接口作用
希望在导出操作之前，加入一些自定义操作，可以用这个接口实现。比如导出的文件进行自定义加密。
注：该接口为流式接口，数据量较大，应避免将数据放入内存，否则存在宕机风险！！
接口内容
主要接口
package com.finebi.dashboard.impl.service.export;
import com.finebi.dashboard.api.service.export.ExportContext;
import com.fr.stable.fun.mark.Mutable;
import java.io.OutputStream;
/**
* 提供导出流修改接口
* Created by Hiram on 2018/11/14.
*/
public interface ExportHandleProvider extends Mutable {
String XML_TAG = "ExportHandleProvider";
int CURRENT_LEVEL = 1;
/**
* 导出流修改
*
* @param originalOutputStream 原始导出流
* @param type 导出类型
* @return 处理后的流
*/
OutputStream handleStream(OutputStream originalOutputStream, ExportType type);
/**
* 导出流修改
*
* @param originalOutputStream 原始导出流
* @param exportContext 导出上下文
* @return
*/
OutputStream handleStream(OutputStream originalOutputStream, ExportContext exportContext);
}
接口接入
<extra-core>
<ExportHandleProvider class="插件自定义实现包全名"/>
</extra-core>
提供给插件的抽象类
package com.finebi.provider.api.export;
import com.finebi.dashboard.impl.service.export.ExportHandleProvider;
import com.finebi.dashboard.impl.service.export.ExportType;
import com.fr.stable.fun.mark.API;
import java.io.OutputStream;
/**
* 计算导出excel的大小
* Created by Hiram on 2018/11/15.
*/
@API(level = ExportHandleProvider.CURRENT_LEVEL)
public abstract class AbstractExportHandleProvider implements ExportHandleProvider {
@Override
public int currentAPILevel() {
return CURRENT_LEVEL;
}
@Override
public String mark4Provider() {
return getClass().getName();
}
@Override
@Deprecated
public OutputStream handleStream(OutputStream originalOutputStream, ExportType type) {
return originalOutputStream;
}
}
历史版本
接口内容
主要接口
package com.finebi.stable.fun;
import com.fr.stable.fun.mark.Mutable;
import java.io.OutputStream;
/**
* Created by Hiram on 2018/11/14.
*/
public interface ExportHandleProvider extends Mutable {
String XML_TAG = "ExportHandleProvider";
int CURRENT_LEVEL = 1;
/**
*
* @param originalOutputStream 原始导出流
* @param type 导出类型
* @return 处理后的流
*/
OutputStream handleStream(OutputStream originalOutputStream, ExportType type);
}
接口接入
<extra-core>
<ExportHandleProvider class="com.fr.plugin.demo.export.CountExportHandle"/>
</extra-core>
示例效果
简单的统计一下导出文件的大小，输出在日志里面。
写一个拦截处理的CountExportHandle，返回一个CountOutputStream，在write时计数，最后在close的时候输出大小。
示例源码
import com.finebi.stable.fun.ExportType;
import com.finebi.stable.fun.impl.AbstractExportHandleProvider;
import java.io.OutputStream;
public class CountExportHandle extends AbstractExportHandleProvider {
@Override
public OutputStream handleStream(OutputStream originalOutputStream, ExportType type) {
return new CountOutputStream(originalOutputStream);
}
}
import com.fr.log.FineLoggerFactory;
import java.io.IOException;
import java.io.OutputStream;
public class CountOutputStream extends OutputStream {
private OutputStream out;
private int count;
public CountOutputStream(OutputStream out) {
this.out = out;
}
@Override
public void write(int b) throws IOException {
count++;
out.write(b);
}
@Override
public void write(byte[] b) throws IOException {
count += b.length;
out.write(b);
}
@Override
public void write(byte[] b, int off, int len) throws IOException {
count += len;
out.write(b, off, len);
}
@Override
public void flush() throws IOException {
out.flush();
}
@Override
public void close() throws IOException {
FineLoggerFactory.getLogger().info("===== export length: {} ======", count);
out.close();
}
}
