方法1：

a.自定义RoundImageView

package app.downloadall.helptool.utils;

import android.annotation.SuppressLint;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Path;
import android.util.AttributeSet;
import android.view.View;

import androidx.appcompat.widget.AppCompatImageView;

public class RoundImageView extends AppCompatImageView {
    float width, height;
    private int defaultRadius = 20;
    private int radius;
    private int leftTopRadius;
    private int rightTopRadius;
    private int rightBottomRadius;
    private int leftBottomRadius;

    public RoundImageView(Context context) {
        this(context, null);
        init(context, null);
    }

    public RoundImageView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
        init(context, attrs);
    }

    public RoundImageView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context, attrs);
    }

    private void init(Context context, AttributeSet attrs) {
        setLayerType(View.LAYER_TYPE_SOFTWARE, null);
        // 读取配置
        @SuppressLint("CustomViewStyleable")
        TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.RoundImageView);
        radius = array.getDimensionPixelOffset(R.styleable.RoundImageView_radius, defaultRadius);
        leftTopRadius = array.getDimensionPixelOffset(R.styleable.RoundImageView_left_top_radius, defaultRadius);
        rightTopRadius = array.getDimensionPixelOffset(R.styleable.RoundImageView_right_top_radius, defaultRadius);
        rightBottomRadius = array.getDimensionPixelOffset(R.styleable.RoundImageView_right_bottom_radius, defaultRadius);
        leftBottomRadius = array.getDimensionPixelOffset(R.styleable.RoundImageView_left_bottom_radius, defaultRadius);


        //如果四个角的值没有设置，那么就使用通用的radius的值。
        if (defaultRadius == leftTopRadius) {
            leftTopRadius = radius;
        }
        if (defaultRadius == rightTopRadius) {
            rightTopRadius = radius;
        }
        if (defaultRadius == rightBottomRadius) {
            rightBottomRadius = radius;
        }
        if (defaultRadius == leftBottomRadius) {
            leftBottomRadius = radius;
        }
        array.recycle();
    }

    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        super.onLayout(changed, left, top, right, bottom);
        width = getWidth();
        height = getHeight();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        //这里做下判断，只有图片的宽高大于设置的圆角距离的时候才进行裁剪
        int maxLeft = Math.max(leftTopRadius, leftBottomRadius);
        int maxRight = Math.max(rightTopRadius, rightBottomRadius);
        int minWidth = maxLeft + maxRight;
        int maxTop = Math.max(leftTopRadius, rightTopRadius);
        int maxBottom = Math.max(leftBottomRadius, rightBottomRadius);
        int minHeight = maxTop + maxBottom;
        if (width >= minWidth && height > minHeight) {
            @SuppressLint("DrawAllocation")
            Path path = new Path();
            //四个角：右上，右下，左下，左上
            path.moveTo(leftTopRadius, 0);
            path.lineTo(width - rightTopRadius, 0);
            path.quadTo(width, 0, width, rightTopRadius);

            path.lineTo(width, height - rightBottomRadius);
            path.quadTo(width, height, width - rightBottomRadius, height);

            path.lineTo(leftBottomRadius, height);
            path.quadTo(0, height, 0, height - leftBottomRadius);

            path.lineTo(0, leftTopRadius);
            path.quadTo(0, 0, leftTopRadius, 0);

            canvas.clipPath(path);
        }
        super.onDraw(canvas);
    }
}

b.添加styles

    <declare-styleable name="RoundImageView">
        <attr name="radius" format="dimension" />
        <attr name="left_top_radius" format="dimension" />
        <attr name="right_top_radius" format="dimension" />
        <attr name="right_bottom_radius" format="dimension" />
        <attr name="left_bottom_radius" format="dimension" />
    </declare-styleable>

方法2：（推荐）

使用ShapeableImageView，这个目前google封装的，还是很好用的

a.添加依赖

    implementation 'com.google.android.material:material:1.3.0'

b.xml直接引用

<com.google.android.material.imageview.ShapeableImageView
        android:id="@+id/im_shapeable"
        app:shapeAppearanceOverlay="@style/ShapeableCircleImageStyle"
        android:layout_width="100dp"
        android:layout_height="126dp"
        android:src="@mipmap/img"/>

c.常用style添加（可根据情况自由添加切角和弧度）

<!-- 带有弧度的图片 -->
<style name="ShapeableCircleImageStyle">
    <item name="cornerFamily">rounded</item>
    <item name="cornerSize">10%</item>
</style>

<!-- 圆形图片（特殊的弧度图片） -->
<style name="ShapeableCircleImageStyle">
    <item name="cornerFamily">rounded</item>
    <item name="cornerSize">50%</item>
</style>

<!-- 右上角90度扇形图片（特殊的弧度图片） -->
<style name="ShapeableTopLeftRoundImageStyle">
    <item name="cornerFamilyTopRight">rounded</item>
    <item name="cornerSizeTopRight">100%</item>
</style>

<!-- 叶子图片（特殊的弧度图片） -->
<style name="ShapeableLeafImageStyle">
    <item name="cornerFamilyTopLeft">rounded</item>
    <item name="cornerFamilyBottomRight">rounded</item>
    <item name="cornerSizeTopLeft">50%</item>
    <item name="cornerSizeBottomRight">50%</item>

<!-- 八边形（切角图片） -->
<style name="ShapeableCutImageStyle">
    <item name="cornerFamily">cut</item>
    <item name="cornerSize">10dp</item>
</style>

<!-- 菱形图片（切角图片） -->
<style name="ShapeablePrismaticImageStyle">
    <item name="cornerFamily">cut</item>
    <item name="cornerSize">50%</item>
</style>

d.边框添加(需要添加padding，否则会有一部分看不到)

<com.google.android.material.imageview.ShapeableImageView
        ...
        app:strokeWidth="2dp"
        android:padding="1dp"
        app:strokeColor="@color/colorPrimaryDark"
        />

方法3：（推荐）

//带弧度
Glide.with(mContext)
                .load(...)
                .apply(RequestOptions.bitmapTransform(new RoundedCorners(20)))
                .into(holder.wImageiew);
//圆
Glide.with(mContext)
                .load(...)
                .apply(RequestOptions.bitmapTransform(new CircleCrop()))
                .into(holder.wImageiew);