小菜鸟

post请求体内容无法重复获取

为什么会无法重复读取呢？

以tomcat为例，在进行请求体读取时实际底层调用的是org.apache.catalina.connector.Request的getInputStream()方法，而该方法返回的是CoyoteInputStream输入流

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public ServletInputStream getInputStream() throws IOException {

    if (usingReader) {
        throw new IllegalStateException(sm.getString("coyoteRequest.getInputStream.ise"));
    }

    usingInputStream = true;
    if (inputStream == null) {
        inputStream = new CoyoteInputStream(inputBuffer);
    }
    return inputStream;

}

在使用CoyoteInputStream进行读取时

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public int read(byte[] b, int off, int len) throws IOException {
  // 如果流关闭，则抛出异常
    if (closed) {
        throw new IOException(sm.getString("inputBuffer.streamClosed"));
    }
// 如果已经读完了，则返回-1
    if (checkByteBufferEof()) {
        return -1;
    }
    int n = Math.min(len, bb.remaining());
    bb.get(b, off, n);
    return n;
}

而流读取完毕都会进行close，这个流close之后，close状态就置为了true，所以导致流无法进行二次读取

异常报错：org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session:

解决方案：

应该是tomcat以前部署的项目有残留，删除掉webapps里面的其他项目，删除掉work文件夹下Catalina下localhost文件夹里其他的项目，删除掉conf文件夹下Catalina下localhost文件夹下的其他项目配置，最后如果还是不行，查看一下conf下的server.xml里是不是有其他项目残留的配置

2018版本的idea

测试页面，无需关心

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