参考下面主要代码：
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public static void draw()
{
int n=10;
for(int i=1;i=n;i++)//控制行数
{
for(int k=n-1;k=i;k--)//打印空格
{
System.out.print(" ");
}
for(int j=1;j=2*i-1;j++)//打印*
{
System.out.print("*");
}
System.out.println();
}
for(int i=n-1;i=1;i--)
{
for(int k=i;k=n-1;k++)
{
System.out.print(" ");
}
for(int j=1;j=2*i-1;j++)
{
System.out.print("*");
}
System.out.println();
}
}
for(i=1;i=4;i++)
{
这个小的for是打印每一行前边的空格
for(j=1;j=4-i;j++)
System.out.print(" ");
这个是打印星星的
for(j=1;j=2*i-1;j++)
System.out.print("*");
这个是打印完一行的换行
System.out.println("");
}
下边的是一样的 只不过每一行的空格和星星数 和上边是翻过来的
for(i=1;i=3;i++)
{
for(j=1;j=i;j++)
System.out.print(" ");
for(j=1;j=7-2*i;j++)
System.out.print("*");
System.out.println("");
}
java.sql.SQLException: 无效的列索引
无效的列索引
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:111)
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:145)
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:207)
atoracle.jdbc.driver.OraclePreparedStatement.setStringInternal(OraclePreparedStatement.java:5328)
atoracle.jdbc.driver.OraclePreparedStatement.setString(OraclePreparedStatement.java:5320)
at untitled5.addreader1.validID(addreader1.java:128)
at untitled5.addreader1.jButton1_actionPerformed(addreader1.java:97)
at untitled5.addreader1_jButton1_actionAdapter.actionPerformed(addreader1.java:175)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
代码：String driverName = "oracle.jdbc.OracleDriver";
Driver driver = (Driver) Class.forName(driverName).newInstance();
//连接数据库
Connection con = DriverManager.getConnection(
"jdbc:oracle:thin:@LONG:1521:orcl", "sysman", "tongfang");
PreparedStatement pstmt = con.prepareStatement(
" insert into reader values(?)");
pstmt.setString(1, str1);
pstmt.setString(2,str2);
pstmt.setString(3,str3);
pstmt.setString(4,str4);
ResultSet res = pstmt.executeQuery();
你好，提问者：
若解决了你的问题请采纳，若有疑问请追问，谢谢！
这个菱形应该是由四个三角形组成，上面两个三角下面两个三角，拼接而成的。下面给你写了个例子：
public class LingXing2 {
public static void main(String[] args) {
//菱形
CeSanJiao(6);
}
public static void CeSanJiao(int number){
//上半截
for(int i=1;i=number;i++){
if(i==1){
for(int lage=1;lagenumber;lage++){
System.out.print("-");
}
for (int j = i; j0 ; j--) {//列数
System.out.print("*");
}
System.out.println();
}else{
//反正三角
for(int j=i;j1;j--){
if(j==i){
for(int lage=1;lage=number-i;lage++){
System.out.print("-");
}
}
System.out.print("*");
}
//正三角
for (int j = i; j0 ; j--) {//列数
System.out.print("*");
}
System.out.println();
}
}
//下半截
for(int i=1;i=number;i++ ){
if(i==(number-1)){
for(int lage=i;lage(number-i-1);lage--){
System.out.print("-");
}
System.out.println("*");
}else{
//反倒三角
for(int j=number-i;j=1;j--){
if(j==(number-i)){
for(int lage=number;lage(number-i);lage--){
System.out.print("-");
}
}
System.out.print("*");
}
//倒三角
for(int j = 1; j number -i; j++){//列数
System.out.print("*");
}
}
System.out.println();
}
}
}
结果：
-----*
----***
---*****
--*******
-*********
***********
-*********
--*******
---*****
----***
-----*