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WebHDFS REST API

2015-11-28 16:46 459 查看

Document Conventions

Monospaced	Used for commands, HTTP request and responses and code blocks.
<Monospaced>	User entered values.
[Monospaced]	Optional values. When the value is not specified, the default value is used.
Italics	Important phrases and words.

Introduction

HTTP REST API支持HDFSFileSystem/FileContext全部的API。HTTP操作和相应的FIleSystem/FileContext里的方法在下个部分展示。HTTP
Query Parameter Dictionary部分详细的描述了默认值和有效值。

Operations

FileSystem URIs vs HTTP URLs

WebHDFS文件系统的scheme是“webhdfs://”。一个WebHDFS文件系统的URL有下面的格式：

[html] view
plaincopy

webhdfs://<HOST>:<HTTP_PORT>/<PATH>

下面是对应的HDFS的URL：

[html] view plaincopyhdfs://<HOST>:<RPC_PORT>/<PATH>

在REST API中，前缀” /webhdfs/v1”插入到path之前，一个query被增加到最后。因此，相应的HTTPURL有下面的格式：

[html] view plaincopyhttp://<HOST>:<HTTP_PORT>/webhdfs/v1/<PATH>?op=...

HDFS Configuration Options

下面是HDFS配置中关于WebHDFS的配置属性：

Property Name	Description
dfs.webhdfs.enabled	Enable/disable WebHDFS in Namenodes and Datanodes
dfs.web.authentication.kerberos.principal	The HTTP Kerberos principal used by Hadoop-Auth in the HTTP endpoint. The HTTP Kerberos principal MUST start with 'HTTP/' per Kerberos HTTP SPNEGO specification.
dfs.web.authentication.kerberos.keytab	The Kerberos keytab file with the credentials for the HTTP Kerberos principal used by Hadoop-Auth in the HTTP endpoint.

Authentication

当security关闭的时候，认证的用户是在user.name查询参数中指定的用户。如果user.name参数没被设置，服务器设置认证用户为默认的web用户，如果是， if
there is any, or return an error response。

当security开启时，认证通过Hadoop Delegation Token或者Kerberos SPNEGO执行。如果在delegation查询参数中设置了一个token，认证的用户就是编码进token的用户。如果delegation查询参数没有被设置，用户通过Kerberos SPNEGO认证。

下面是用curl命令工具的一下例子：

1. 当security关闭时的认证：

[html] view
plaincopy

curl -i"http://<HOST>:<PORT>/webhdfs/v1/<PATH>?[user.name=<USER>&]op=..."

2. 当security开启时用Kerberos SPNEGO认证

[html] view
plaincopy

curl -i--negotiate -u :"http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=..."

3. 当security开启时用Hadoop Delegation Token认证

[html] view
plaincopy

curl -i"http://<HOST>:<PORT>/webhdfs/v1/<PATH>?delegation=<TOKEN>&op=..."

也可以查看：HTTP Authentication。

Proxy Users

当代理用户特性开启时，一个代理用户P可以代表其他的用户U提交一个请求。U的用户名必须在doas查询参数中被指定，除非一个Delegation Token出现在认证中。在这种情况下，用户P和U的信息必须被编码进Delegation Token。

l 当security关闭时一个代理请求：

[html] view
plaincopy

curl -i"http://<HOST>:<PORT>/webhdfs/v1/<PATH>?[user.name=<USER>&]doas=<USER>&op=..."

l 当security开启时用KerberosSPNEGO验证代理请求：

[html] view
plaincopy

curl -i --negotiate -u :"http://<HOST>:<PORT>/webhdfs/v1/<PATH>?doas=<USER>&op=..."

l 当security开启时用HadoopDelegation Token验证大力请求：

[html] view
plaincopy

curl -i"http://<HOST>:<PORT>/webhdfs/v1/<PATH>?delegation=<TOKEN>&op=..."

File and Directory Operations

Create and Write to a File

u Step1：提交一个HTTP PUT请求，没有自动接着重定向，也没有发送文件数据。

[html] view plaincopycurl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=CREATE
[&overwrite=<true|false>][&blocksize=<LONG>][&replication=<SHORT>]
[&permission=<OCTAL>][&buffersize=<INT>]"

请求被重定向到要被写入数据的文件所在的DataNode：

[html] view plaincopyHTTP/1.1 307 TEMPORARY_REDIRECT
Location: http://<DATANODE>:<PORT>/webhdfs/v1/<PATH>?op=CREATE... Content-Length: 0

u  Step2：用要被写入的文件数据，提交另一个HTTP PUT请求到上边返回的Header中的location的URL。

curl -i -X PUT -T <LOCAL_FILE> "http://<DATANODE>:<PORT>/webhdfs/v1/<PATH>?op=CREATE..."

客户端收到一个201 Created响应，content-length为0，location header是一个WebHDFS的URL。

[html] view plaincopyHTTP/1.1 201 Created
Location: webhdfs://<HOST>:<PORT>/<PATH>
Content-Length: 0

注意：分成create/append两步的原因是为了防止客户端在重定向之前发送数据。这个问题在HTTP/1.1中可以通过加入"Expect: 100-continue"头解决。不幸的是，还有一些软件库存在bug（例如Jetty 6HTTP Server and java 6 HTTP Client），它们没有正确的实现"Expect: 100-continue"。通过create/append两步是针对软件库bug一个临时的解决方案。

See also: overwrite, blocksize, replication, permission, buffersize, FileSystem.create

Append toa file

u Step1：提交一个HTTP POST请求，不会自动接着重定向，不发送文件数据：

[html] view
plaincopy

curl -i -X POST"http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=APPEND[&buffersize=<INT>]"

请求重定向到要被附加数据的文件所在的datanode：

[html] view
plaincopy

HTTP/1.1 307TEMPORARY_REDIRECT

Location:http://<DATANODE>:<PORT>/webhdfs/v1/<PATH>?op=APPEND...

Content-Length: 0

u Step2：使用上边的Location Header的URL提交另一个附加了要被增加到文件的数据的HTTP POST请求：

[html] view
plaincopy

curl -i -X POST -T<LOCAL_FILE>"http://<DATANODE>:<PORT>/webhdfs/v1/<PATH>?op=APPEND..."

客户端收到一个content-length为0的响应：

[html] view
plaincopy

HTTP/1.1 200 OK

Content-Length: 0

可以参考上一部分的描述，为什么这个操作需要两步。

See also: buffersize, FileSystem.append

Concat File(s)

u 提交一个HTTP POST请求

[html] view
plaincopy

curl -i -X POST"http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=CONCAT&sources=<PATHS>"

客户端收到一个content-length=0的响应：

[html] view
plaincopy

HTTP/1.1 200 OK

Content-Length: 0

See also: sources, FileSystem.concat

Open and Read
a File

u 提交一个自动重定向的HTTPGET请求

[html] view
plaincopy

curl -i -L"http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=OPEN

[&offset=<LONG>][&length=<LONG>][&buffersize=<INT>]"

请求重定向到可以读到文件数据的DataNode：

[html] view
plaincopy

HTTP/1.1 307TEMPORARY_REDIRECT

Location:http://<DATANODE>:<PORT>/webhdfs/v1/<PATH>?op=OPEN...

Content-Length: 0

客户端接着重定向到DataNode，然后读取文件数据：

[html] view
plaincopy

HTTP/1.1 200 OK

Content-Type:application/octet-stream

Content-Length: 22

Hello, webhdfsuser!

See also: offset, length, buffersize, FileSystem.open

Make a Directory

u 提交一个HTTP PUT请求

[html] view
plaincopy

curl -i -X PUT"http://<HOST>:<PORT>/<PATH>?op=MKDIRS[&permission=<OCTAL>]"

客户端收到一个Boolean JSON对象：

[html] view
plaincopy

HTTP/1.1 200 OK

Content-Type:application/json

Transfer-Encoding:chunked

{"boolean":true}

See also: permission, FileSystem.mkdirs

Create a
Symbolic Link

u 提交一个HTTP PUT请求。

[html] view
plaincopy

curl -i -X PUT"http://<HOST>:<PORT>/<PATH>?op=CREATESYMLINK

&destination=<PATH>[&createParent=<true|false>]"

客户端收到一个Content-Length=0的响应：

[html] view plaincopyHTTP/1.1 200 OK
Content-Length: 0

See also: destination, createParent, FileSystem.createSymlink

Rename a
File/Directory

u 提交一个HTTP PUT请求。

[html] view
plaincopy

curl -i -X PUT"<HOST>:<PORT>/webhdfs/v1/<PATH>?op=RENAME&destination=<PATH>"

客户端收到一个Boolean JSON对象：

[html] view
plaincopy

HTTP/1.1 200 OK

Content-Type:application/json

Transfer-Encoding:chunked

{"boolean":true}

See also: destination, FileSystem.rename

Delete a
File/Directory

u 提交一个DELETE请求：

[html] view
plaincopy

curl -i -X DELETE"http://<host>:<port>/webhdfs/v1/<path>?op=DELETE

[&recursive=<true|false>]"

客户端收到一个Boolean JSON对象：

[html] view
plaincopy

HTTP/1.1 200 OK

Content-Type:application/json

Transfer-Encoding:chunked

{"boolean":true}

See also: recursive, FileSystem.delete

Status
of a File/Directory

u 提交一个HTTP GET请求

[html] view
plaincopy

curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=GETFILESTATUS"

客户端收到一个FIleStatus JSON对象的响应：

[html] view
plaincopy

HTTP/1.1 200 OK

Content-Type:application/json

Transfer-Encoding:chunked

{

"FileStatus":

{

"accessTime" : 0,

"blockSize" : 0,

"group" : "supergroup",

"length" : 0, //in bytes, zero for directories

"modificationTime":1320173277227,

"owner" : "webuser",

"pathSuffix" : "",

"permission" : "777",

"replication" : 0,

"type" : "DIRECTORY" //enum {FILE, DIRECTORY, SYMLINK}

}

}

See also: FileSystem.getFileStatus

List a Directory

u 提交一个HTTP GET请求。

[html] view
plaincopy

curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=LISTSTATUS"

客户端收到一个FileStatuses JSON对象：

[html] view
plaincopy

HTTP/1.1 200 OK

Content-Type:application/json

Content-Length: 427

{

"FileStatuses":

{

"FileStatus":

[

{

"accessTime" : 1320171722771,

"blockSize" : 33554432,

"group" : "supergroup",

"length" : 24930,

"modificationTime":1320171722771,

"owner" : "webuser",

"pathSuffix" : "a.patch",

"permission" : "644",

"replication" : 1,

"type" : "FILE"

},

{

"accessTime" : 0,

"blockSize" : 0,

"group" : "supergroup",

"length" : 0,

"modificationTime": 1320895981256,

"owner" : "szetszwo",

"pathSuffix" : "bar",

"permission" : "711",

"replication" : 0,

"type" : "DIRECTORY"

},

...

]

}

}

See also: FileSystem.listStatus

Other File System Operations

Get
Content Summary of aDirectory

u 提交一个HTTP GET请求。

[html] view
plaincopy

curl -i"http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=GETCONTENTSUMMARY"

客户端收到一个ContentSummaryJSON对象：

[html] view plaincopyHTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked

{
"ContentSummary":
{
"directoryCount": 2,
"fileCount"     : 1,
"length"        : 24930,
"quota"         : -1,
"spaceConsumed" : 24930,
"spaceQuota"    : -1
}
}

Get File Checksum

u 提交一个HTTP GET请求。

[html] view plaincopycurl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=GETFILECHECKSUM"

提交被重定向到一个DataNode。

[html] view plaincopyHTTP/1.1 307 TEMPORARY_REDIRECT
Location: http://<DATANODE>:<PORT>/webhdfs/v1/<PATH>?op=GETFILECHECKSUM... Content-Length: 0

客户端跟着重定向到DataNode然后接收一个FileChecksum JSON对象：

[html] view plaincopyHTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked

{
"FileChecksum":
{
"algorithm": "MD5-of-1MD5-of-512CRC32",
"bytes"    : "eadb10de24aa315748930df6e185c0d ...",
"length"   : 28
}
}

See also: FileSystem.getFileChecksum

Get Home Directory

u 提交一个HTTP GET请求

[html] view plaincopycurl -i "http://<HOST>:<PORT>/webhdfs/v1/?op=GETHOMEDIRECTORY"

客户端收到一个PATH JSON对象的响应：

[html] view plaincopyHTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked

{"Path": "/user/szetszwo"}

Set Permission

u 提交一个HTTP PUT请求

[html] view plaincopycurl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=SETPERMISSION
[&permission=<OCTAL>]"

客户端收到一个Content-Length=0的响应：

[html] view plaincopyHTTP/1.1 200 OK
Content-Length: 0

See also: permission, FileSystem.setPermission

Set Owner

u 提交一个HTTP PUT请求

[html] view plaincopycurl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=SETOWNER
[&owner=<USER>][&group=<GROUP>]"

客户端收到一个Content-Length=0的响应：

[html] view plaincopyHTTP/1.1 200 OK
Content-Length: 0

See also: owner, group, FileSystem.setOwner

Set Replication
Factor

u 提交一个HTTP PUT请求

[html] view plaincopycurl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=SETREPLICATION
[&replication=<SHORT>]"

客户端收到一个Boolean JSON对象的请求

[html] view plaincopycurl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=SETREPLICATION
[&replication=<SHORT>]"

See also: replication, FileSystem.setReplication

Set
Access or ModificationTime

u 提交一个HTTP PUT请求

[html] view plaincopycurl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=SETTIMES
[&modificationtime=<TIME>][&accesstime=<TIME>]"

客户端收到一个Content-Length=0的响应：

[html] view plaincopyHTTP/1.1 200 OK
Content-Length: 0

See also: modificationtime, accesstime, FileSystem.setTimes

Modify ACL Entries

u 提交一个HTTP PUT请求

[html] view plaincopycurl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=MODIFYACLENTRIES
&aclspec=<ACLSPEC>"

客户端收到一个content-length=0的请求

[html] view plaincopyHTTP/1.1 200 OK
Content-Length: 0

Remove ACL Entries

u 提交一个HTTP PUT请求

[html] view plaincopycurl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=REMOVEACLENTRIES
&aclspec=<ACLSPEC>"

客户端收到一个Content-Length=0的响应：

[html] view plaincopyHTTP/1.1 200 OK
Content-Length: 0

Remove Default
ACL

u 提交一个HTTP PUT请求

[html] view plaincopycurl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=REMOVEDEFAULTACL"

客户端收到一个Content-Length=0的响应

[html] view plaincopyHTTP/1.1 200 OK
Content-Length: 0

Remove ACL

u 提交一个HTTP PUT请求

[html] view plaincopycurl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=REMOVEACL"

客户端收到一个Content-Length=0响应：

[html] view plaincopyHTTP/1.1 200 OK
Content-Length: 0

Set ACL

u 提交一个HTTP PUT请求

[html] view plaincopycurl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=SETACL
&aclspec=<ACLSPEC>"

客户端收到一个Content-Length=0的请求

[html] view plaincopyHTTP/1.1 200 OK
Content-Length: 0

Get ACL Status

u 提交一个HTTP GET请求

[html] view plaincopycurl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=GETACLSTATUS"

客户端收到一个AclStatus JSON对象格式的响应：

[html] view plaincopyHTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked

{
"AclStatus": {
"entries": [
"user:carla:rw-",
"group::r-x"
],
"group": "supergroup",
"owner": "hadoop",
"stickyBit": false
}
}

Delegation
Token Operations

Get Delegation Token

u 提交一个HTTP GET 请求

[html] view plaincopycurl -i "http://<HOST>:<PORT>/webhdfs/v1/?op=GETDELEGATIONTOKEN&renewer=<USER>"

客户端收到一个Token JSON对象的请求

[html] view plaincopyHTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked

{
"Token":
{
"urlString": "JQAIaG9y..."
}
}

See also: renewer, FileSystem.getDelegationToken

Get Delegation Tokens

u 提交一个HTTP GET请求

[html] view plaincopycurl -i "http://<HOST>:<PORT>/webhdfs/v1/?op=GETDELEGATIONTOKENS&renewer=<USER>"

客户端收到一个Tokens JSON格式的响应：

[html] view plaincopyHTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked

{
"Tokens":
{
"Token":
[
{
"urlString":"KAAKSm9i ..."
}
]
}
}

See also: renewer, FileSystem.getDelegationTokens

Renew Delegation
Token

u 提交一个HTTP PUT 请求

[html] view plaincopycurl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/?op=RENEWDELEGATIONTOKEN&token=<TOKEN>"

客户端收到一个long型JSON对象的响应：

[html] view plaincopyHTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked

{"long": 1320962673997}           //the new expiration time

See also: token, FileSystem.renewDelegationToken

Cancel
Delegation Token

u 提交一个HTTP PUT请求

[html] view plaincopycurl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/?op=CANCELDELEGATIONTOKEN&token=<TOKEN>"

客户端收到一个Content-Length=0的响应：

[html] view plaincopyHTTP/1.1 200 OK
Content-Length: 0

See also: token, FileSystem.cancelDelegationToken

Error Responses

当一个操作失败，服务器可能会抛出一个错误。一个error响应的JSON格式定义在 RemoteExceptionJSON
Schema中。下面的表格显示了exception到HTTP响应码的映射。

HTTP Response
Codes

Exceptions	HTTP Response Codes
IllegalArgumentException	400 Bad Request
UnsupportedOperationException	400 Bad Request
SecurityException	401 Unauthorized
IOException	403 Forbidden
FileNotFoundException	404 Not Found
RumtimeException	500 Internal Server Error

下面是一些错误的响应的例子。

Illegal
Argument Exception

[html] view plaincopyHTTP/1.1 400 Bad Request
Content-Type: application/json
Transfer-Encoding: chunked

{
"RemoteException":
{
"exception"    : "IllegalArgumentException",
"javaClassName": "java.lang.IllegalArgumentException",
"message"      : "Invalid value for webhdfs parameter \"permission\": ..."
}
}

Security Exception

[html] view plaincopyHTTP/1.1 401 Unauthorized
Content-Type: application/json
Transfer-Encoding: chunked

{
"RemoteException":
{
"exception"    : "SecurityException",
"javaClassName": "java.lang.SecurityException",
"message"      : "Failed to obtain user group information: ..."
}
}

Access
Control Exception

[html] view plaincopyHTTP/1.1 403 Forbidden
Content-Type: application/json
Transfer-Encoding: chunked

{
"RemoteException":
{
"exception"    : "AccessControlException",
"javaClassName": "org.apache.hadoop.security.AccessControlException",
"message"      : "Permission denied: ..."
}
}

File Not
Found Exception

[html] view plaincopyHTTP/1.1 404 Not Found
Content-Type: application/json
Transfer-Encoding: chunked

{
"RemoteException":
{
"exception"    : "FileNotFoundException",
"javaClassName": "java.io.FileNotFoundException",
"message"      : "File does not exist: /foo/a.patch"
}
}

[html] view
plaincopy

HTTP/1.1 404 Not Found

Content-Type: application/json

Transfer-Encoding: chunked

{

"RemoteException":

{

"exception" : "FileNotFoundException",

"javaClassName": "java.io.FileNotFoundException",

"message" : "File does not exist: /foo/a.patch"

}

}

JSON Schemas

所有的操作，除了OPEN，要么返回一个长度为0的响应要么返回一个JSON响应。对于OPEN，响应是一个自己流。下面是JSON的模式。

注意，additionalProperties是默认值是一个空的模式，这允许为附加的属性设置任何值。因此，所有的WebHDFS JSON响应允许任何额外的属性。但是，如果响应中加入了额外的属性，为了保持兼容，它们被认为是可选的属性。

ACL Status
JSON Schema

[html] view plaincopy{
"name"      : "AclStatus",
"properties":
{
"AclStatus":
{
"type"      : "object",
"properties":
{
"entries":
{
"type": "array"
"items":
{
"description": "ACL entry.",
"type": "string"
}
},
"group":
{
"description": "The group owner.",
"type"       : "string",
"required"   : true
},
"owner":
{
"description": "The user who is the owner.",
"type"       : "string",
"required"   : true
},
"stickyBit":
{
"description": "True if the sticky bit is on.",
"type"       : "boolean",
"required"   : true
},
}
}
}
}

Boolean JSON
Schema

[html] view plaincopy{
"name"      : "boolean",
"properties":
{
"boolean":
{
"description": "A boolean value",
"type"       : "boolean",
"required"   : true
}
}
}

See also: MKDIRS, RENAME, DELETE, SETREPLICATION

ContentSummary
JSON Schema

[html] view plaincopy{
"name"      : "ContentSummary",
"properties":
{
"ContentSummary":
{
"type"      : "object",
"properties":
{
"directoryCount":
{
"description": "The number of directories.",
"type"       : "integer",
"required"   : true
},
"fileCount":
{
"description": "The number of files.",
"type"       : "integer",
"required"   : true
},
"length":
{
"description": "The number of bytes used by the content.",
"type"       : "integer",
"required"   : true
},
"quota":
{
"description": "The namespace quota of this directory.",
"type"       : "integer",
"required"   : true
},
"spaceConsumed":
{
"description": "The disk space consumed by the content.",
"type"       : "integer",
"required"   : true
},
"spaceQuota":
{
"description": "The disk space quota.",
"type"       : "integer",
"required"   : true
}
}
}
}
}

FileChecksum
JSON Schema

[html] view plaincopy{
"name"      : "FileChecksum",
"properties":
{
"FileChecksum":
{
"type"      : "object",
"properties":
{
"algorithm":
{
"description": "The name of the checksum algorithm.",
"type"       : "string",
"required"   : true
},
"bytes":
{
"description": "The byte sequence of the checksum in hexadecimal.",
"type"       : "string",
"required"   : true
},
"length":
{
"description": "The length of the bytes (not the length of the string).",
"type"       : "integer",
"required"   : true
}
}
}
}
}

FileStatus
JSON Schema

[html] view plaincopy{
"name"      : "FileStatus",
"properties":
{
"FileStatus": fileStatusProperties      //See FileStatus Properties
}
}

FileStatus
Properties

使用了Javascript的语法定义一个fileStatusProperties ，因此它可被在FileStatus和FileStatusesJSON模式中使用。

[html] view plaincopyvar fileStatusProperties =
{
"type"      : "object",
"properties":
{
"accessTime":
{
"description": "The access time.",
"type"       : "integer",
"required"   : true
},
"blockSize":
{
"description": "The block size of a file.",
"type"       : "integer",
"required"   : true
},
"group":
{
"description": "The group owner.",
"type"       : "string",
"required"   : true
},
"length":
{
"description": "The number of bytes in a file.",
"type"       : "integer",
"required"   : true
},
"modificationTime":
{
"description": "The modification time.",
"type"       : "integer",
"required"   : true
},
"owner":
{
"description": "The user who is the owner.",
"type"       : "string",
"required"   : true
},
"pathSuffix":
{
"description": "The path suffix.",
"type"       : "string",
"required"   : true
},
"permission":
{
"description": "The permission represented as a octal string.",
"type"       : "string",
"required"   : true
},
"replication":
{
"description": "The number of replication of a file.",
"type"       : "integer",
"required"   : true
},
"symlink":                                         //an optional property
{
"description": "The link target of a symlink.",
"type"       : "string"
},
"type":
{
"description": "The type of the path object.",
"enum"       : ["FILE", "DIRECTORY", "SYMLINK"],
"required"   : true
}
}
};

FileStatuses
JSON Schema

一个FileStatuses JSON对象代表一个FileStatusJSON对象的数组。

[html] view plaincopy{
"name"      : "FileStatuses",
"properties":
{
"FileStatuses":
{
"type"      : "object",
"properties":
{
"FileStatus":
{
"description": "An array of FileStatus",
"type"       : "array",
"items"      : fileStatusProperties      //See FileStatus Properties
}
}
}
}
}

See also: FileStatus Properties, LISTSTATUS, FileStatus

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章节导航

WebHDFS REST API

Document Conventions

Introduction

Operations

HTTP GET

HTTP PUT

HTTP POST

HTTP DELETE

FileSystem URIs vs HTTP URLs

HDFS Configuration Options

Authentication

Proxy Users

File and Directory Operations

Create and Write to a File

Append toa file

Concat File(s)

Open and Reada File

Make a Directory

Create aSymbolic Link

Rename aFile/Directory

Delete aFile/Directory

Statusof a File/Directory

List a Directory

Other File System Operations

GetContent Summary of aDirectory

Get File Checksum

Get Home Directory

Set Permission

Set Owner

Set ReplicationFactor

SetAccess or ModificationTime

Modify ACL Entries

Remove ACL Entries

Remove DefaultACL

Remove ACL

Set ACL

Get ACL Status

DelegationToken Operations

Get Delegation Token

Get Delegation Tokens

Renew DelegationToken

CancelDelegation Token

Error Responses

HTTP ResponseCodes

IllegalArgument Exception

Security Exception

AccessControl Exception

File NotFound Exception

[html] viewplaincopyHTTP/1.1 404 Not FoundContent-Type: application/jsonTransfer-Encoding: chunked{"RemoteException":{"exception" : "FileNotFoundException","javaClassName": "java.io.FileNotFoundException","message" : "File does not exist: /foo/a.patch"}}JSON Schemas

ACL StatusJSON Schema

Boolean JSONSchema

ContentSummaryJSON Schema

FileChecksumJSON Schema

FileStatusJSON Schema

FileStatusProperties

FileStatusesJSON Schema

Open and Read
a File

Create a
Symbolic Link

Rename a
File/Directory

Delete a
File/Directory

Status
of a File/Directory

Get
Content Summary of aDirectory

Set Replication
Factor

Set
Access or ModificationTime

Remove Default
ACL

Delegation
Token Operations

Renew Delegation
Token

Cancel
Delegation Token

HTTP Response
Codes

Illegal
Argument Exception

Access
Control Exception

File Not
Found Exception

[html] view
plaincopy

HTTP/1.1 404 Not Found

Content-Type: application/json

Transfer-Encoding: chunked

{

"RemoteException":

{

"exception" : "FileNotFoundException",

"javaClassName": "java.io.FileNotFoundException",

"message" : "File does not exist: /foo/a.patch"

}

}

JSON Schemas

ACL Status
JSON Schema

Boolean JSON
Schema

ContentSummary
JSON Schema

FileChecksum
JSON Schema

FileStatus
JSON Schema

FileStatus
Properties

FileStatuses
JSON Schema