Clob

java.lang.Object
- ohos.data.orm.Clob

所有已实现的接口:

Clob
```
public class Clob
extends Object
implements Clob
```
Represents a Clob that stores Character Large Objects (CLOBs) in the Object Relational Mapping (ORM) system.
This class is inherited from java.sql.Clob. The Clob is used to store a CLOB as a column value in a row of a database table.

从以下版本开始:

1

SystemCapability

SystemCapability.Data#DATA_APPDATAMGR

构造器概要

构造器
构造器说明

Clob(String charData)
A constructor used to create a Clob object from data of the char type.

构造器
构造器	说明
`Clob(String charData)`	A constructor used to create a `Clob` object from data of the char type.

方法概要

所有方法实例方法具体方法
限定符和类型	方法	说明
`boolean`	`equals(Object object)`	Indicates whether some other object is "equal to" this one.
`void`	`free()`	This method frees the `Clob` object and releases the resources the resources that it holds.
`InputStream`	`getAsciiStream()`	Retrieves the `CLOB` value designated by this `Clob` object as an ascii stream.
`Reader`	`getCharacterStream()`	Retrieves the `CLOB` value designated by this `Clob` object as a `java.io.Reader` object (or as a stream of characters).
`Reader`	`getCharacterStream(long pos, long length)`	Returns a `Reader` object that contains a partial `Clob` value, starting with the character specified by pos, which is length characters in length.
`String`	`getSubString(long startPos, int length)`	Retrieves a copy of the specified substring in the `CLOB` value designated by this `Clob` object.
`int`	`hashCode()`	Returns a hash code value for the object.
`long`	`length()`	Retrieves the number of characters in the `CLOB` value designated by this `Clob` object.
`long`	`position(String stringToFind, long startPos)`	Retrieves the character position at which the specified substring `searchstr` appears in the SQL `CLOB` value represented by this `Clob` object.
`long`	`position(Clob clob, long startPos)`	Retrieves the character position at which the specified `Clob` object `searchstr` appears in this `Clob` object.
`OutputStream`	`setAsciiStream(long indexToWriteAt)`	Retrieves a stream to be used to write Ascii characters to the `CLOB` value that this `Clob` object represents, starting at position `pos`.
`Writer`	`setCharacterStream(long indexToWriteAt)`	Retrieves a stream to be used to write a stream of Unicode characters to the `CLOB` value that this `Clob` object represents, at position `pos`.
`int`	`setString(long pos, String str)`	Writes the given Java `String` to the `CLOB` value that this `Clob` object designates at the position `pos`.
`int`	`setString(long pos, String str, int offset, int length)`	Writes `len` characters of `str`, starting at character `offset`, to the `CLOB` value that this `Clob` represents.
`String`	`toString()`	Returns a string representation of the object.
`void`	`truncate(long length)`	Truncates the `CLOB` value that this `Clob` designates to have a length of `len` characters.

从类继承的方法 java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- 构造器详细资料
  - Clob
```
public Clob(String charData)
```
    A constructor used to create a Clob object from data of the char type.
    CLOB is usually used to store text data.
    
    参数:
    
    charData - Indicates the data of the char type.
    
    从以下版本开始:
    
    1
- 方法详细资料
  - length
```
public long length()
```
    从接口复制的说明: Clob
    
    Retrieves the number of characters in the CLOB value designated by this Clob object.
    
    指定者:
    
    length 在接口中 Clob
    
    返回:
    
    length of the CLOB in characters
  - getSubString
```
public String getSubString(long startPos,
                           int length)
```
    Retrieves a copy of the specified substring in the CLOB value designated by this Clob object. The substring begins at position pos and has up to length consecutive characters.
    
    指定者:
    
    getSubString 在接口中 Clob
    
    参数:
    
    startPos - Indicates the position of the first character of the string to extract. The value ranges from 1 to 2147483648.
    
    length - the number of consecutive characters to be copied; the value for length must be 0 or greater
    
    返回:
    
    a String that is the specified substring in the CLOB value designated by this Clob object
    
    从以下版本开始:
    
    1
  - getCharacterStream
```
public Reader getCharacterStream()
```
    从接口复制的说明: Clob
    
    Retrieves the CLOB value designated by this Clob object as a java.io.Reader object (or as a stream of characters).
    
    指定者:
    
    getCharacterStream 在接口中 Clob
    
    返回:
    
    a java.io.Reader object containing the CLOB data
    
    另请参阅:
    
    Clob.setCharacterStream(long)
  - getAsciiStream
```
public InputStream getAsciiStream()
```
    从接口复制的说明: Clob
    
    Retrieves the CLOB value designated by this Clob object as an ascii stream.
    
    指定者:
    
    getAsciiStream 在接口中 Clob
    
    返回:
    
    a java.io.InputStream object containing the CLOB data
    
    另请参阅:
    
    Clob.setAsciiStream(long)
  - position
```
public long position(String stringToFind,
                     long startPos)
```
    Retrieves the character position at which the specified substring searchstr appears in the SQL CLOB value represented by this Clob object. The search begins at position start.
    
    指定者:
    
    position 在接口中 Clob
    
    参数:
    
    stringToFind - Indicates the string to be found in the clob.
    
    startPos - Indicates the start position. The value ranges from 1 to 2147483648.
    
    返回:
    
    the position at which the substring appears or -1 if it is not present; the first position is 1
    
    从以下版本开始:
    
    1
  - position
```
public long position(Clob clob,
                     long startPos)
```
    Retrieves the character position at which the specified Clob object searchstr appears in this Clob object. The search begins at position start.
    
    指定者:
    
    position 在接口中 Clob
    
    参数:
    
    startPos - Indicates the start position. The value ranges from 1 to 2147483648.
    
    clob - the Clob object for which to search
    
    返回:
    
    the position at which the Clob object appears or -1 if it is not present; the first position is 1
    
    从以下版本开始:
    
    1
  - setString
```
public int setString(long pos,
                     String str)
```
    Writes the given Java String to the CLOB value that this Clob object designates at the position pos. The string will overwrite the existing characters in the Clob object starting at the position pos. If the end of the Clob value is reached while writing the given string, then the length of the Clob value will be increased to accommodate the extra characters.
    Note: If the value specified for pos is greater then the length+1 of the CLOB value then the behavior is undefined. Some JDBC drivers may throw a SQLException while other drivers may support this operation.
    
    指定者:
    
    setString 在接口中 Clob
    
    参数:
    
    pos - Indicates the start position. The value ranges from 1 to 2147483648.
    
    str - Indicates the string to be replaced in th clob.
    
    返回:
    
    the number of characters written
    
    从以下版本开始:
    
    1
  - setString
```
public int setString(long pos,
                     String str,
                     int offset,
                     int length)
```
    Writes len characters of str, starting at character offset, to the CLOB value that this Clob represents. The string will overwrite the existing characters in the Clob object starting at the position pos. If the end of the Clob value is reached while writing the given string, then the length of the Clob value will be increased to accommodate the extra characters.
    Note: If the value specified for pos is greater then the length+1 of the CLOB value then the behavior is undefined. Some JDBC drivers may throw a SQLException while other drivers may support this operation.
    
    指定者:
    
    setString 在接口中 Clob
    
    参数:
    
    pos - Indicates the start position. The value ranges from 1 to 2147483648.
    
    str - the string to be written to the CLOB value that this Clob object represents
    
    offset - the offset into str to start reading the characters to be written
    
    length - the number of characters to be written
    
    返回:
    
    the number of characters written
    
    从以下版本开始:
    
    1
  - setAsciiStream
```
public OutputStream setAsciiStream(long indexToWriteAt)
```
    Retrieves a stream to be used to write Ascii characters to the CLOB value that this Clob object represents, starting at position pos. Characters written to the stream will overwrite the existing characters in the Clob object starting at the position pos. If the end of the Clob value is reached while writing characters to the stream, then the length of the Clob value will be increased to accommodate the extra characters.
    Note: If the value specified for pos is greater then the length+1 of the CLOB value then the behavior is undefined. Some JDBC drivers may throw a SQLException while other drivers may support this operation.
    
    指定者:
    
    setAsciiStream 在接口中 Clob
    
    参数:
    
    indexToWriteAt - Indicates the position where to start writing ASCII characters to this Clob instance. The value ranges from 1 to 2147483648.
    
    返回:
    
    the stream to which ASCII encoded characters can be written
    
    从以下版本开始:
    
    1
    
    另请参阅:
    
    Clob.getAsciiStream()
  - setCharacterStream
```
public Writer setCharacterStream(long indexToWriteAt)
```
    Retrieves a stream to be used to write a stream of Unicode characters to the CLOB value that this Clob object represents, at position pos. Characters written to the stream will overwrite the existing characters in the Clob object starting at the position pos. If the end of the Clob value is reached while writing characters to the stream, then the length of the Clob value will be increased to accommodate the extra characters.
    Note: If the value specified for pos is greater then the length+1 of the CLOB value then the behavior is undefined. Some JDBC drivers may throw a SQLException while other drivers may support this operation.
    
    指定者:
    
    setCharacterStream 在接口中 Clob
    
    参数:
    
    indexToWriteAt - Indicates the position where to start writing a stream of Unicode characters to this Clob instance. The value ranges from 1 to 2147483648.
    
    返回:
    
    a stream to which Unicode encoded characters can be written
    
    从以下版本开始:
    
    1
    
    另请参阅:
    
    Clob.getCharacterStream()
  - truncate
```
public void truncate(long length)
```
    从接口复制的说明: Clob
    
    Truncates the CLOB value that this Clob designates to have a length of len characters.
    Note: If the value specified for pos is greater then the length+1 of the CLOB value then the behavior is undefined. Some JDBC drivers may throw a SQLException while other drivers may support this operation.
    
    指定者:
    
    truncate 在接口中 Clob
    
    参数:
    
    length - the length, in characters, to which the CLOB value should be truncated
  - free
```
public void free()
```
    从接口复制的说明: Clob
    
    This method frees the Clob object and releases the resources the resources that it holds. The object is invalid once the free method is called.
    After free has been called, any attempt to invoke a method other than free will result in a SQLException being thrown. If free is called multiple times, the subsequent calls to free are treated as a no-op.
    
    指定者:
    
    free 在接口中 Clob
  - getCharacterStream
```
public Reader getCharacterStream(long pos,
                                 long length)
```
    从接口复制的说明: Clob
    
    Returns a Reader object that contains a partial Clob value, starting with the character specified by pos, which is length characters in length.
    
    指定者:
    
    getCharacterStream 在接口中 Clob
    
    参数:
    
    pos - the offset to the first character of the partial value to be retrieved. The first character in the Clob is at position 1.
    
    length - the length in characters of the partial value to be retrieved.
    
    返回:
    
    Reader through which the partial Clob value can be read.
  - equals
```
public boolean equals(Object object)
```
    从类复制的说明: Object
    Indicates whether some other object is "equal to" this one.
    The equals method implements an equivalence relation on non-null object references:
    - It is reflexive: for any non-null reference value x, x.equals(x) should return true.
    - It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
    - It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
    - It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
    - For any non-null reference value x, x.equals(null) should return false.
    The equals method for class Object implements the most discriminating possible equivalence relation on objects; that is, for any non-null reference values x and y, this method returns true if and only if x and y refer to the same object (x == y has the value true).
    Note that it is generally necessary to override the hashCode method whenever this method is overridden, so as to maintain the general contract for the hashCode method, which states that equal objects must have equal hash codes.
    覆盖:
    
    equals 在类中 Object
    
    参数:
    
    object - the reference object with which to compare.
    
    返回:
    
    true if this object is the same as the obj argument; false otherwise.
    
    另请参阅:
    
    Object.hashCode(), HashMap
  - hashCode
```
public int hashCode()
```
    从类复制的说明: Object
    Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by HashMap.
    The general contract of hashCode is:
    - Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
    - If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result.
    - It is not required that if two objects are unequal according to the Object.equals(java.lang.Object) method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.
    As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the Java™ programming language.)
    覆盖:
    
    hashCode 在类中 Object
    
    返回:
    
    a hash code value for this object.
    
    另请参阅:
    
    Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)
  - toString
```
public String toString()
```
    从类复制的说明: Object
    Returns a string representation of the object. In general, the toString method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.
    The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:
    getClass().getName() + '@' + Integer.toHexString(hashCode())
    覆盖:
    
    toString 在类中 Object
    
    返回:
    
    a string representation of the object.

类 Clob

构造器概要

方法概要

从类继承的方法 java.lang.Object

构造器详细资料

Clob

方法详细资料

length

getSubString

getCharacterStream

getAsciiStream

position

position

setString

setString

setAsciiStream

setCharacterStream

truncate

free

getCharacterStream

equals

hashCode

toString