标签：blog ar io os sp for java on 数据
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
标签：blog ar io os sp for java on 数据
原文地址：http://www.cnblogs.com/wangyt223/p/4168211.html
