java的IO流重用

使用jersey的过滤器获取参数时发现,用

InputStream entityStream = requestContext.getEntityStream();

获取转换完成之后,进入到接口中参数就消失了,查阅资料之后发现是转换成流之后只能使用一次,所以要在转换器中重新set进一个流

//支持流重用
        InputStream entityStream = requestContext.getEntityStream();
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        byte[] buffer = new byte[1024];
        int len;
        while ((len = entityStream.read(buffer)) > -1) {
            baos.write(buffer, 0, len);
        }
        baos.flush();
        String requestStr = this.inputStreamToString(new ByteArrayInputStream(baos.toByteArray()));
        requestContext.setEntityStream(new ByteArrayInputStream(baos.toByteArray()));

        String[] arrs = requestStr.split("&");
        LinkedList<String> param = Lists.newLinkedList();
        if(null!=arrs){
            for (int i=0;i<arrs.length;i++){
                param.add(arrs[i]);
            }
        }

//获取参数的方法
public String inputStreamToString(InputStream in) throws IOException {
        StringBuffer out = new StringBuffer();
        byte[] b = new byte[4096];
        for (int n; (n = in.read(b)) != -1;) {
            out.append(new String(b, 0, n));
        }
        return out.toString();
    }