String name = new String(request.getParameter("ZY").getBytes("ISO-8859-1"), "UTF-8"); System.out.print(name); if (name == null || name.isEmpty()) { %> <a href="SouSuo.jsp">请输入中药名称，点击返回重新输入</a> <% }else{ Connection conn = null; Statement stmt = null; ResultSet rs = null; try { conn = SQLConn.openDB(); stmt = conn.createStatement(); // 执行查询等操作 String sql = "select ZYName,YLName,YDY,YX,GX,ZhongYao.ZZ as ZZ from Yaolei,ZhongYao where Yaolei.YLID=ZhongYao.YLID"; PreparedStatement pstmt = conn.prepareStatement(sql); //pstmt.setString(1, "%" + name + "%"); rs = pstmt.executeQuery(); int count = 0; if(rs.next()){ while (rs.next()) { String ZYName = rs.getString("ZYName"); System.out.print(name); if (name.trim().equals(ZYName.trim())) { // if (name.trim().equals(A.trim())) { %>为什么name.trim().equals(ZYName.trim())不成立

可能是因为在数据库中查询出来的`ZYName`前或后有空格或其他不可见字符，导致字符串比较不相等。可以将`System.out.print()`语句放在字符串比较之前打印出两个字符串的值，看看是否有差异。另外，可以使用`String`类的`trim()`方法去除字符串两端的空格再进行比较，或者使用`equalsIgnoreCase()`方法忽略大小写进行比较。具体代码可以这样写：

String name = new String(request.getParameter("ZY").getBytes("ISO-8859-1"), "UTF-8");
System.out.println("name: " + name); // 打印name的值
if (name == null || name.isEmpty()) {
    // ...
} else {
    Connection conn = null;
    Statement stmt = null;
    ResultSet rs = null;
    try {
        conn = SQLConn.openDB();
        stmt = conn.createStatement();
        String sql = "select ZYName,YLName,YDY,YX,GX,ZhongYao.ZZ as ZZ from Yaolei,ZhongYao where Yaolei.YLID=ZhongYao.YLID";
        PreparedStatement pstmt = conn.prepareStatement(sql);
        rs = pstmt.executeQuery();
        int count = 0;
        while (rs.next()) {
            String ZYName = rs.getString("ZYName").trim(); // 去除两端空格
            System.out.println("ZYName: " + ZYName); // 打印ZYName的值
            if (name.equalsIgnoreCase(ZYName)) { // 忽略大小写比较
                // ...
            }
        }
    } catch (Exception e) {
        // ...
    } finally {
        // ...
    }
}