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（转）在JAVA实现DataTable对象（三）——DataTable对象实现
大家都是行家，我就直接上代码了，我这个代码应该还是能看懂的，嘻嘻….
1: import java.util.ArrayList; 2: import java.util.List; 3: 6: 7: public final class DataTable { 8: 9: private DataRowCollection rows; //用于保存DataRow的集合对象 10: private DataColumnCollection columns; //用于保存DataColumn的对象 11: private String tableName; //表名 12: private boolean readOnly = false; 13: private int nextRowIndex = 0; 14: private DataExpression dataExpression; 15: private Object tag; 16: 17: public DataTable() { 18: this.columns = new DataColumnCollection(); 19: this.rows = new DataRowCollection(); 20: this.rows.setColumns(columns); 21: dataExpression = new DataExpression(this); 22: } 23: 24: public DataTable(String dataTableName) { 25: this(); 26: this.tableName = dataTableName; 27: } 28: 29: public int getTotalCount() { 30: return rows.size(); 31: } 32: 33: public boolean isReadOnly() { 34: return this.readOnly; 35: } 36: 37: public void setReadOnly(boolean readOnly) { 38: this.readOnly = readOnly; 39: } 40: 41: /** 42: * 功能描述： 返回表名 43: * @param 44: */ 45: public String getTableName() { 46: return this.tableName; 47: } 48: 49: /** 50: * 功能描述： 设置表名 51: * @param 52: */ 53: public void setTableName(String tableName) { 54: this.tableName = tableName; 55: } 56: 57: /** 58: * 功能描述： 返回该表引用的封装类 59: * @param 60: * @return: DataRowCollection 61: */ 62: public DataRowCollection getRows() { 63: return this.rows; 64: } 65: 66: public DataColumnCollection getColumns() { 67: return this.columns; 68: } 69: 70: /** 71: * 功能描述： 获取指定行指定列的数据 72: * @param 73: * @return: Object 74: */ 75: 76: public Object getValue(int row, 77: String colName) { 78: return this.rows.get(row).getValue(colName); 79: } 80: 81: public Object getValue(int row, 82: int col) { 83: return this.rows.get(row).getValue(col); 84: } 85: 86: /** 87: * 功能描述： 为该表数据新建一行 88: * @param 89: * @return: DataRow 90: */ 91: public DataRow newRow() throws Exception { 92: DataRow tempRow = new DataRow(this); 93: nextRowIndex = nextRowIndex < this.rows.size() ? this.rows.size() 94: : nextRowIndex; 95: tempRow.setColumns(this.columns); 96: tempRow.setRowIndex(nextRowIndex++); 97: return tempRow; 98: } 99: 100: public void setValue(int row, 101: int col, 102: Object value) { 103: this.rows.get(row).setValue(col, value); 104: } 105: 106: public void setValue(int row, 107: String colName, 108: Object value) { 109: this.rows.get(row).setValue(colName, value); 110: } 111: 112: /** 113: * @param tag 114: */ 115: public void setTag(Object tag) { 116: this.tag = tag; 117: } 118: 119: /** 120: * @return the tag 121: */ 122: public Object getTag() { 123: return tag; 124: } 125: 126: public DataColumn addColumn(String columnName, 127: int dataType) throws Exception { 128: return this.columns.addColumn(columnName, dataType); 129: } 130: 131: public boolean addRow(DataRow row) throws Exception { 132: if (row.getRowIndex() > this.rows.size()) 133: row.setRowIndex(this.rows.size()); 134: return this.rows.add(row); 135: } 136: 137: //以下为数据表扩展方法实现集合 138: /** 139: * 功能描述： 返回符合过滤条件的数据行集合，并返回 140: * @param 141: * @return: DataTable 142: */ 143: public List<DataRow> select(String filterString) { 144: List<DataRow> rows = new ArrayList<DataRow>(); 145: if (StringUtil.isNotEmpty(filterString)) { 146: for (Object row : this.rows) { 147: DataRow currentRow = (DataRow) row; 148: if ((Boolean) dataExpression.compute(filterString, 149: currentRow.getItemMap())) { 150: rows.add(currentRow); 151: } 152: } 153: return rows; 154: } else { 155: return this.rows; 156: } 157: } 158: 159: /** 160: * 功能描述： 对当前表进行查询 过滤，并返回指定列集合拼装的DataTable对象 161: * @param 162: * @return: DataTable 163: */ 164: public DataTable select(String filterString, 165: String[] columns, 166: boolean distinct) throws Exception { 167: DataTable result = new DataTable(); 168: List<DataRow> rows = select(filterString); 169: //构造表结构 170: for (String c : columns) { 171: DataColumn dc = this.columns.get(c); 172: DataColumn newDc = new DataColumn(dc.getColumnName(), 173: dc.getDataType()); 174: newDc.setCaptionName(dc.getCaptionName()); 175: result.columns.add(newDc); 176: } 177: //填充数据 178: for (DataRow r : rows) { 179: DataRow newRow = result.newRow(); 180: newRow.copyFrom(r); 181: result.addRow(newRow); 182: } 183: return result; 184: } 185: 186: public DataTable select(String tableName, 187: String selectField, 188: String filterString, 189: String groupField) { 190: DataTable result = new DataTable(); 191: // 192: return result; 193: } 194: 195: /** 196: * 功能描述： 根据指定表达式对符合过滤条件的数据进行计算 197: * @param 198: * @return: Object 199: * @author: James Cheung 200: * @version: 2.0 201: */ 202: public Object compute(String expression, 203: String filter) { 204: return dataExpression.compute(expression, select(filter)); 205: } 206: 207: public Object max(String columns, 208: String filter) { 209: return null; 210: } 211: 212: public Object min(String columns, 213: String filter) { 214: return null; 215: } 216: 217: public Object avg(String columns, 218: String filter) { 219: return null; 220: } 221: 222: public Object max(String columns, 223: String filter, 224: String groupBy) { 225: return null; 226: } 227: 228: public Object min(String columns, 229: String filter, 230: String groupBy) { 231: return null; 232: } 233: 234: public Object avg(String columns, 235: String filter, 236: String groupBy) { 237: return null; 238: } 239: 240: private List<DataColumn> getColumns(String colString) { 241: List<DataColumn> columns = new ArrayList<DataColumn>(); 242: 243: return columns; 244: } 245: }（转）在JAVA实现DataTable对象（三）——DataTable对象实现
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