org.ttzero.excel.entity

类 SharedStrings

java.lang.Object

org.ttzero.excel.entity.SharedStrings

所有已实现的接口:

Closeable, AutoCloseable, Storable

@TopNS(prefix="",
       value="sst",
       uri="http://schemas.openxmlformats.org/spreadsheetml/2006/main")
public class SharedStrings
extends Object
implements Storable, Closeable

A workbook collects the strings of all text cells in a global list, the Shared String Table. This table is located in the record SST in the Workbook Globals Substream.

SST saves characters and strings sequentially. When writing a string, it first determines whether it exists. If it exists, returns the index in the Table (zero base), otherwise add it in to the last element of Table and returns the current subscript. Introduced Google BloomFilter to increase filtering speed, the BloomFilter estimates the amount of data to be 1 million, and the false positive rate is 0.3%. When the number exceeds 2^17, it will be converted to inline string.

A hot zone is also designed internally to cache multiple occurrences, the default size is 512, and the LRU elimination algorithm is used. If the cache misses, it will be read from in temp file and flushed to the cache.

Characters are handled differently. ASCII characters use the built-in array cache subscript. The over 0x7F characters will be converted to strings and searched using strings.

作者:

guanquan.wang on 2017/10/10.

方法概要

限定符和类型	方法和说明
void	close()
int	get(char c) Getting the character value index (zero base)
int	get(String key) Getting the string value from cache (zero base)
void	writeTo(Path root) Write to disk

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

方法详细资料

get

public int get(char c)
        throws IOException

Getting the character value index (zero base)

参数:

c - the character value

返回:

the index in ShareString

抛出:

IOException - if I/O error occur

get

public int get(String key)
        throws IOException

Getting the string value from cache (zero base)

参数:

key - the string value

返回:

index of the string in the SST -1 if cache full, please write as 'inlineStr'

抛出:

IOException - if I/O error occur

writeTo

public void writeTo(Path root)
             throws IOException

从接口复制的说明: Storable

Write to disk

指定者:

writeTo 在接口中 Storable

参数:

root - the parent path

抛出:

IOException - if io error occur

close

public void close()
           throws IOException

指定者:

close 在接口中 Closeable

指定者:

close 在接口中 AutoCloseable

抛出:

IOException