"Java & JSP Tips: Best Practices Every Developer Should Know"

 

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🧠 Introduction

Java and JSP (JavaServer Pages) have been at the heart of enterprise web development for decades. While modern frameworks are gaining traction, JSP is still widely used in financial, educational, and government systems — especially in places like Sri Lanka and India.

In this post, I’ll share practical Java & JSP tips based on real-world experience. Whether you’re maintaining legacy code or building from scratch, these tips will help you write cleaner, more secure, and maintainable web applications.

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🔧 Section 1: Java Tips for Web Developers

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✅ 1. Always Use Meaningful Variable and Method Names

Avoid names like temp, a1, or xyz. Instead, use:

java
double interestRate;
String customerName;
public double calculateMonthlyPayment(...) { ... }

This improves readability and team collaboration.

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✅ 2. Use StringBuilder Instead of String for Concatenation in Loops

Java's String is immutable. So, concatenation in loops can hurt performance.

java
StringBuilder sb = new StringBuilder();
for (int i = 0; i < 100; i++) {
    sb.append("Line ").append(i).append("\n");
}

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✅ 3. Always Handle Exceptions Gracefully

Avoid catch(Exception e) unless necessary. Be specific:

java
try {
   Connection con = DriverManager.getConnection(...);
} catch (SQLException e) {
   System.out.println("Database error: " + e.getMessage());
}

And don’t forget to log it or show a user-friendly message.

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✅ 4. Use PreparedStatement to Prevent SQL Injection

Unsafe:

java
Statement stmt = con.createStatement();
stmt.execute("SELECT * FROM users WHERE name = '" + name + "'");

Safe:

java
PreparedStatement ps = con.prepareStatement("SELECT * FROM users WHERE name = ?");
ps.setString(1, name);

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✅ 5. Modularize Repeated Code (DRY Principle)

Create utility classes or methods for repeated logic such as:

• Date formatting

• Number formatting

• DB connections

Example:

java
public static Connection getConnection() throws SQLException {
   return DriverManager.getConnection(DB_URL, USER, PASS);
}

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🌐 Section 2: JSP Tips and Best Practices

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✅ 1. Avoid Using Scriptlets (<% %>) in JSP

Modern JSP should use JSTL or EL (Expression Language) instead of:

jsp
<% out.print(user.getName()); %>

Use:

jsp
${user.name}

It keeps your pages clean and maintainable.

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✅ 2. Use MVC Pattern – Never Mix Business Logic in JSP

JSP should be for view only. Move logic to:

• Servlets

• JavaBeans

• Controllers

Bad:

jsp
<%
Connection con = DriverManager.getConnection(...);
%>

Good:

jsp
<!-- Call JavaBean or forward from Servlet -->
${user.name}

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✅ 3. Always Set Content Type and Encoding

At the top of each JSP:

jsp
<%@ page pageEncoding="UTF-8" contentType="text/html;charset=UTF-8" %>

This avoids character encoding issues (especially with Sinhala/Tamil content).

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✅ 4. Avoid Including Heavy Files with <%@ include %>

Use jsp:include when you want dynamic inclusion:

jsp
<jsp:include page="menu.jsp" />

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✅ 5. Use JSTL & EL for Cleaner Code

Add JSTL library in your project and use it for:

• Loops (<c:forEach>)

• Conditionals (<c:if> / <c:choose>)

• Formatting (<fmt:formatDate>)

Example:

jsp
<c:forEach var="item" items="${itemList}">
  <li>${item.name}</li>
</c:forEach>

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🔐 Bonus: Security Tips

• Validate input on both client and server

• Use HTTPS and encrypt sensitive data

• Implement session timeout and logout

• Prevent XSS with ${fn:escapeXml(data)}

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🧩 Real-World Scenario

Imagine you are building a banking app with JSP and Java:

❌ Don't:

• Embed SQL directly in JSP

• Handle transactions in UI

• Use Java code in JSP

✅ Do:

• Handle DB in a BankDAO.java class

• Use Servlet for request/response logic

• Use JSP just to display output

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🚀 Conclusion

Java and JSP may seem "old school", but when used properly, they are rock-solid and scalable. By following these best practices, you’ll avoid common pitfalls, improve performance, and write more maintainable code.

Keep it clean. Keep it modular. Keep coding.

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📥 Call to Action

Want a sample JSP project (login + CRUD + dashboard)?
Leave a comment or message and I’ll send it to you via IdeaInk!