field.java

我费了好大劲才找到的一款非常全的OA办公自动化软件源码

            return null; // we don't have this information
        }

        if (fullName == null) {
            StringBuffer fullOriginalNameBuf = new StringBuffer(getOriginalTableName()
                                                                    .length()
                    + 1 + getOriginalName().length());
            fullOriginalNameBuf.append(this.originalTableName);

            // much faster to append a char than a String
            fullOriginalNameBuf.append('.');
            fullOriginalNameBuf.append(this.originalColumnName);
            this.fullOriginalName = fullOriginalNameBuf.toString();
            fullOriginalNameBuf = null;
        }

        return this.fullOriginalName;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public long getLength() {
        return length;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public boolean isMultipleKey() {
        return ((colFlag & 8) > 0);
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public int getMysqlType() {
        return mysqlType;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public String getName() {
        if (this.name == null) {
            this.name = getStringFromBytes(this.nameStart, this.nameLength);
        }

        return name;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public String getOriginalName() {
        if ((this.originalColumnName == null)
                && (this.originalColumnNameStart != -1)
                && (this.originalColumnNameLength != -1)) {
            this.originalColumnName = getStringFromBytes(this.originalColumnNameStart,
                    this.originalColumnNameLength);
        }

        return this.originalColumnName;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public String getOriginalTableName() {
        if ((this.originalTableName == null)
                && (this.originalTableNameStart != -1)
                && (this.originalTableNameLength != -1)) {
            this.originalTableName = getStringFromBytes(this.originalTableNameStart,
                    this.originalTableNameLength);
        }

        return this.originalTableName;
    }

    /**
     * Returns amount of correction that
     * should be applied to the precision value.
     *
     * Different versions of MySQL report different
     * precision values.
     *
     * @return the amount to adjust precision value by.
     */
    public int getPrecisionAdjustFactor() {
        return this.precisionAdjustFactor;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public boolean isPrimaryKey() {
        return ((colFlag & 2) > 0);
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public int getSQLType() {
        return sqlType;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public String getTable() {
        return getTableName();
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public String getTableName() {
        if (tableName == null) {
            tableName = getStringFromBytes(tableNameStart, tableNameLength);
        }

        return tableName;
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public boolean isUniqueKey() {
        return ((colFlag & 4) > 0);
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public boolean isUnsigned() {
        return ((colFlag & 32) > 0);
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public boolean isZeroFill() {
        return ((colFlag & 64) > 0);
    }

    /**
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public String toString() {
    	return this.getDatabaseName() + " . " +  this.getTableName() + "(" + this.getOriginalTableName() + ") . " + this.getName() + "(" + this.getOriginalName() + ")";
       
    }

    int getDecimals() {
        return colDecimals;
    }

    boolean isNotNull() {
        return ((colFlag & 1) > 0);
    }

    /**
     * Is this field _definitely_ not writable?
     * 
     * @return true if this field can not be written to in an INSERT/UPDATE
     * statement.
     */
    boolean isReadOnly() throws SQLException {
    	if (this.connection.getIO().versionMeetsMinimum(4, 1, 0)) {
    		String orgColumnName = getOriginalName();
    		String orgTableName = getOriginalTableName();
    		
    		return !(orgColumnName != null && orgColumnName.length() > 0 &&
    				orgTableName != null && orgTableName.length() > 0);
    	} else {
    		return false;
    	}
    }
    
    /**
     * Create a string with the correct charset encoding from the
     * byte-buffer that contains the data for this field
     */
    private String getStringFromBytes(int stringStart, int stringLength) {
        if ((stringStart == -1) || (stringLength == -1)) {
            return null;
        }

        String stringVal = null;

        if (connection != null) {
            if (connection.useUnicode()) {
            	
                String encoding = this.connection.getCharacterSetMetadata();
                
                if (encoding == null) {
                	encoding = connection.getEncoding();
                }
                
                if (encoding != null) {
                   
					SingleByteCharsetConverter converter = null;
					
					if (this.connection != null) {
						converter = this.connection.getCharsetConverter(encoding);
					}
                    
                    if (converter != null) { // we have a converter
                        stringVal = converter.toString(buffer, stringStart,
                                stringLength);
                    } else {
                        // we have no converter, use JVM converter 
                        byte[] stringBytes = new byte[stringLength];

                        int endIndex = stringStart + stringLength;
                        int pos = 0;

                        for (int i = stringStart; i < endIndex; i++) {
                            stringBytes[pos++] = buffer[i];
                        }

                        try {
                            stringVal = new String(stringBytes, encoding);
                        } catch (UnsupportedEncodingException ue) {
                            throw new RuntimeException(
                                "Unsupported character encoding '" + encoding
                                + "'");
                        }
                    }
                } else {
                    // we have no encoding, use JVM standard charset
                    stringVal = StringUtils.toAsciiString(buffer, stringStart,
                            stringLength);
                }
            } else {
                // we are not using unicode, so use JVM standard charset 
                stringVal = StringUtils.toAsciiString(buffer, stringStart,
                        stringLength);
            }
        } else {
            // we don't have a connection, so punt 
            stringVal = StringUtils.toAsciiString(buffer, stringStart,
                    stringLength);
        }

        return stringVal;
    }
    
    //
    // MySQL only has one protocol-level BLOB type that it exposes
    // which is FIELD_TYPE_BLOB, although we can divine what the
    // actual type is by the length reported ...
    //
    private void setBlobTypeBasedOnLength() {
    	 if (this.length == MysqlDefs.LENGTH_TINYBLOB) {
    	 	this.mysqlType = MysqlDefs.FIELD_TYPE_TINY_BLOB;
    	 } else if (this.length == MysqlDefs.LENGTH_BLOB) {
    	 	this.mysqlType = MysqlDefs.FIELD_TYPE_BLOB;
    	 } else if (this.length == MysqlDefs.LENGTH_MEDIUMBLOB) {
    	 	this.mysqlType = MysqlDefs.FIELD_TYPE_MEDIUM_BLOB;
    	 } else if (this.length == MysqlDefs.LENGTH_LONGBLOB) {
    	 	this.mysqlType = MysqlDefs.FIELD_TYPE_LONG_BLOB;
    	 }
    }
}