社区应用 最新帖子 精华区 社区服务 会员列表 统计排行 社区论坛任务 迷你宠物
  • 10597阅读
  • 0回复

http断点续传简单实现(java)

发帖
8
铜板
1641
人品值
95
贡献值
0
交易币
0
好评度
8
信誉值
0
金币
0
所在楼道
/* y7>iz6N  
**SiteFileFetch.java VF\{ra;  
*/ -RGPt D@  
package NetFox; FQ U\0<5  
import java.io.*; g`kY]lu  
import java.net.*; ZOp^`c9~  
mU50pM~/i  
]+mjOks~  
public class SiteFileFetch extends Thread { r)Or\HL  
`Uv)Sf{  
DTPay1]6  
SiteInfoBean siteInfoBean = null; //文件信息Bean )Ea8{m!   
long[] nStartPos; //开始位置 Hc M~  
long[] nEndPos; //结束位置 J6DnPaw-G  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 +)zDA:2Wa"  
long nFileLength; //文件长度 I|Z/`9T  
boolean bFirst = true; //是否第一次取文件 "2%>M  
boolean bStop = false; //停止标志 6eM6[  
File tmpFile; //文件下载的临时信息 k'g$2  
DataOutputStream output; //输出到文件的输出流 p<q].^M  
c& 3#-DNI  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) <8f(eP\*F  
public SiteFileFetch(SiteInfoBean bean) throws IOException NaF(\j  
{  U7E  
siteInfoBean = bean; '5AvT: ^u  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); .?B{GnB>  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); l^ARW E  
if(tmpFile.exists ()) wEE2a56L-  
{ 6p#g0t  
bFirst = false; I'dj.  
read_nPos(); +GYS26  
} W+.{4 K  
else te)n{K",  
{ 8`*`nQhWa  
nStartPos = new long[bean.getNSplitter()]; H/^B.5RYE>  
nEndPos = new long[bean.getNSplitter()]; BMdSf(l  
}  +tIz[+u  
kff ZElV  
V'j@K!)~xR  
9_GokU P_  
} o*-9J2V=J  
-3` "E%9  
  La9r  
public void run() a&C.=  
{ 4#_$@ r  
//获得文件长度 R5~gH6K|  
//分割文件 7D   
//实例FileSplitterFetch  #I;D  
//启动FileSplitterFetch线程 3?@?-q2g  
//等待子线程返回 7lR<@$q  
try{ |0kXCq  
if(bFirst) Y87XLvig}  
{ +TF8WZZF.d  
nFileLength = getFileSize(); \"'\MA  
if(nFileLength == -1) z{|LQt6q  
{ :@/"abv  
System.err.println("File Length is not known!"); 1M+oTIN  
} N 'i,>  
else if(nFileLength == -2) -6`;},Yr  
{ a8zZgIV  
System.err.println("File is not access!"); mB`D}g$  
} lufeieW  
else 781]THY=  
{ Ig9d#c  
for(int i=0;i<nStartPos.length;i++) g_vm&~U/'  
{ GD&htob(  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); w4,]2Ccn.  
} /&(1JqzlB  
for(int i=0;i<nEndPos.length-1;i++) m6i%DE  
{ J(e7{aRJ9  
nEndPos = nStartPos[i+1]; hg8Be6G <  
} DvYwCgLR  
nEndPos[nEndPos.length-1] = nFileLength; %'0&ElQ  
} 4-V)_U#8  
} O,|\"b1(  
3cixQzb}u  
?mU\ N0o  
//启动子线程 3;l"=#5  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; M|8 3HTJ  
for(int i=0;i<nStartPos.length;i++) W Y:s gG  
{ 6G}c1nWU  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h55>{)(E  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), MwAJ(  
nStartPos,nEndPos,i); 8teJ*sz  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .YR8v1Cp  
fileSplitterFetch.start(); 'I v_mig  
} *ik/p  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #tDW!Xv?  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Y)Tl<  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5g>wV  
nEndPos = " + nFileLength); yFjVKp'P  
// fileSplitterFetch[nPos.length-1].start(); |dk[cX>  
8W -@N  
1 i3k  
//等待子线程结束 xA #H0?a]  
//int count = 0; k':s =IXW  
//是否结束while循环 6t7fa<  
boolean breakWhile = false; vq>l>as9O  
k>5O`Y:  
;LQ9#M?  
while(!bStop) ,Sg33N ?  
{ opD-vDa h  
write_nPos(); mmP U  
Utility.sleep(500); L/i(KF{  
breakWhile = true; ARWZ; GX  
 D:JS)+]  
9i%9   
for(int i=0;i<nStartPos.length;i++) :1;Q(9:v  
{ %K1")s  
if(!fileSplitterFetch.bDownOver) bfdVED  
{ p/*"4-S  
breakWhile = false; #epy%>  
break; pbLGe'  
} d~Mg vh'  
} IzUo0D*@  
if(breakWhile) af'@h:  
break; *aRX \ TnN  
<n^3uXzD  
Gx'TkU=  
//count++; fu]N""~  
//if(count>4) H~o <AmE0!  
// siteStop(); /S~m)$vu  
} A,#2^dR  
SaO3 zz@L  
.=<$S#x^Hb  
System.err.println("文件下载结束!"); E FY@Y[  
} o8ppMM8_R[  
catch(Exception e){e.printStackTrace ();} XUS vhr$|  
} !#}7{  
FS@A8Bb  
H l<$a"K7\  
//获得文件长度 Cq\I''~8  
public long getFileSize() :2y"3azxk  
{ "HlgRp]u  
int nFileLength = -1; Ns=AjhLc z  
try{ "b,%8  
URL url = new URL(siteInfoBean.getSSiteURL()); +iA=y=;blH  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NXU`wnVJ  
httpConnection.setRequestProperty("User-Agent","NetFox"); aE/D*.0NI  
lddp^ #f  
cdTsRS;E  
int responseCode=httpConnection.getResponseCode(); |B^G:7c  
if(responseCode>=400) xs!p|  
{ ~uj;qq  
processErrorCode(responseCode); ln<]-)&C  
return -2; //-2 represent access is error 6rX_-Mm6w  
} Xy7Z38G  
TH?9< C-C  
 +sZUJ  
String sHeader; ;t(f1rPyE  
qf8[!5GM  
/:[2'_Xl  
for(int i=1;;i++) {{!Y]\2S  
{ H{(]9{  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); I1"MPx{  
//Utility.log(in.readLine()); YQ]\uT>}&  
sHeader=httpConnection.getHeaderFieldKey(i); !;3PG9n3|h  
if(sHeader!=null) a07=tD  
{ uaw <  
if(sHeader.equals("Content-Length")) @i%YNI5*  
{  76H!)={  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .p&Yr%~  
break; n&Yk<  
} ]Pc^#=(R0  
} A3{0q>CC  
else ziEz.Wn"  
break; '&yeQ   
} jbmTmh1q  
} <@uOCRb V  
catch(IOException e){e.printStackTrace ();} la^ DjHA$  
catch(Exception e){e.printStackTrace ();} vkcRm`.  
#A<P6zJXR  
0q6I;$H  
Utility.log(nFileLength); ~<9{#uM  
B'weok  
%f ju G  
return nFileLength; z#Nl@NO&  
} :`Az/U[  
.EP6oKA  
vqNsZ 8|`  
//保存下载信息(文件指针位置) 5#2 F1NX  
private void write_nPos() hOk00az  
{ ,mFsM!|  
try{ R;}22s  
output = new DataOutputStream(new FileOutputStream(tmpFile)); yR71%]*.  
output.writeInt(nStartPos.length); =A!S/;z>  
for(int i=0;i<nStartPos.length;i++) [L~@uAMw:  
{ ,/,9j{|"j  
// output.writeLong(nPos); :Vuf6,  
output.writeLong(fileSplitterFetch.nStartPos); O'DW5hBL0  
output.writeLong(fileSplitterFetch.nEndPos); lU2c_4  
} rrBAQY|.  
output.close(); KMK`F{  
} HOi C  
catch(IOException e){e.printStackTrace ();} E]} n(  
catch(Exception e){e.printStackTrace ();} A74920X`W  
} ,|T7hTn=  
-yx/7B5@  
nU z7|y  
//读取保存的下载信息(文件指针位置) g:#d l\k  
private void read_nPos() !<\Br  
{ v"Jgw;3  
try{ W WG /k17  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); pW?& J>\6  
int nCount = input.readInt(); }_OM$nzj  
nStartPos = new long[nCount]; fI|[Z+"  
nEndPos = new long[nCount]; 1|Q vN1?  
for(int i=0;i<nStartPos.length;i++) 5g ;ac~g  
{ d/,E2i{I7  
nStartPos = input.readLong(); 8cxai8  
nEndPos = input.readLong(); NAFsFngqH  
} 'r} fZ  
input.close(); UlovXb  
} v3RcwySk  
catch(IOException e){e.printStackTrace ();} V5rp.~   
catch(Exception e){e.printStackTrace ();} ^]c6RE_  
} tj1JB%  
qr(`&hB-L  
4? (W%?  
private void processErrorCode(int nErrorCode) ! . HnGb+  
{ g!J0L7 i|  
System.err.println("Error Code : " + nErrorCode); /Z%>ArAx  
} @R2at  
4Yjx{5QSAG  
H AB#pd9  
//停止文件下载 $#NQ <3  
public void siteStop() uG J"!K  
{ sd0r'jb  
bStop = true; _YHu96H;  
for(int i=0;i<nStartPos.length;i++) @,H9zrjVFZ  
fileSplitterFetch.splitterStop(); HZ"Evl|n  
f-RK,#^?,  
E;(Rm>lB  
} a P()|js  
} ^ @=^;nB  
//负责部分文件的抓取 B |{I:[  
**FileSplitterFetch.java 3:CO{=`\7B  
*/ ;h/pnmhP  
package NetFox; 2j&@ p>  
{padD p  
lC?Icn|o  
import java.io.*; /!&R9!6 :  
import java.net.*; ]]iPEm"@  
1cJsj  
o|8`>!hF  
public class FileSplitterFetch extends Thread { 8g/F)~s^F  
V64L,u#`l  
7^e +  
String sURL; //File URL 1(dj[3Mt  
long nStartPos; //File Snippet Start Position )mcEQ-!b  
long nEndPos; //File Snippet End Position fys  
int nThreadID; //Thread's ID ]F*3"y?)2  
boolean bDownOver = false; //Downing is over ^HA %q8| n  
boolean bStop = false; //Stop identical `iG,H[t+j  
FileAccessI fileAccessI = null; //File Access interface VM=+afY5M  
D&:yMp(  
o4^Fo p  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @e2}BhB2  
{ NY B[Zyp  
this.sURL = sURL; 12`_;[37  
this.nStartPos = nStart; v> z@  
this.nEndPos = nEnd; \ZXLX'-  
nThreadID = id; 7*H:Ob)9k  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 x8#ODuH  
} SAv<&  
`k{& /]  
{bNXedZ\  
public void run() omX?Bl  
{ $.mQ7XDA9  
while(nStartPos < nEndPos && !bStop) TYgQJW?  
{ |$lwkC)O  
u:gtOjk2  
e]>ori 8  
try{ 3 /6/G}s  
URL url = new URL(sURL); ZU2laqa_  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A2H4k|8  
httpConnection.setRequestProperty("User-Agent","NetFox"); g[z.*y/  
String sProperty = "bytes="+nStartPos+"-"; Ss ?CfRM  
httpConnection.setRequestProperty("RANGE",sProperty); :VA.QrKW  
Utility.log(sProperty); M^madx6`  
_GtBP'iN  
U yqXMbw@  
InputStream input = httpConnection.getInputStream(); B5am1y{P#  
//logResponseHead(httpConnection); 8nNsrat  
C 'mL&  
Hgc=M  
byte[] b = new byte[1024]; W  0[N0c  
int nRead; Uu p(6`7  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) keAcKhj  
{ }E^S]hdvz  
nStartPos += fileAccessI.write(b,0,nRead); VV_l$E$  
//if(nThreadID == 1) B0UJq./`  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R!x: C!{  
} 7 6fIC  
Pt< s* (  
JcO08n  
Utility.log("Thread " + nThreadID + " is over!"); B/uniR^x  
bDownOver = true; w Fn[9_`*  
//nPos = fileAccessI.write (b,0,nRead); ~4,I7c7  
} ><?BqRm+  
catch(Exception e){e.printStackTrace ();} `m~syKz4A  
} V`hu,Y;%  
} e_3CSx8Cc  
D$e B ,~  
jdqj=Yc  
//打印回应的头信息 WgGm#I>K  
public void logResponseHead(HttpURLConnection con) 7Hw<ojkt  
{ }odV_WT  
for(int i=1;;i++) |01?w|  
{ ,Fqz e/  
String header=con.getHeaderFieldKey(i); pb;")Q'  
if(header!=null) (zo^Nn9VJ  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =d;Vk  
Utility.log(header+" : "+con.getHeaderField(header)); !cEG}(|h  
else $A\m>*@  
break; ekSY~z=/u  
} :K.4n  
} P1zK2sL_  
!E\[SjY@J  
}qPhx6nP  
public void splitterStop() Zy"=y+e!E;  
{ tB(4Eq \  
bStop = true; f>Td)s1 M  
} ),^eA  
6iezLG 5  
PFSLyV*  
} W=}Okq)x9I  
yWIm&Q:  
Xo5$X7m  
/* h\[\\m O  
**FileAccess.java /ONV5IkPy  
*//文件访问(定位,写) !3&kQpF  
package NetFox; Eh8Pwt7C@  
import java.io.*; 2h~-  
jh ez  
y f1CXldi  
public class FileAccessI implements Serializable{ ;1AG3P'  
EYS>0Y  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =Ov7C[(  
RandomAccessFile oSavedFile; Do-^S:.  
long nPos; {i{xo2<1"  
#~ v4caNx  
H. ,;-  
public FileAccessI() throws IOException [ .yJV`  
{ =5]n\"/  
this("",0); ?^!,vh  
} yOXO)u1n  
Y Z}cB  
K\! #4>yd  
public FileAccessI(String sName,long nPos) throws IOException C*Vd-U  
{ l)8&Ip  
oSavedFile = new RandomAccessFile(sName,"rw"); < +`(\  
this.nPos = nPos; ReB7vpd  
oSavedFile.seek(nPos); F}?<v8#z0  
} x4?10f(9=  
o3Ot.9L  
f|3q^wjs  
public synchronized int write(byte[] b,int nStart,int nLen) N_wp{4 0/  
{ ks(SjEF  
int n = -1; Ws[D{dS/  
try{ a=}*mF[ug  
oSavedFile.write(b,nStart,nLen); ;6;H*Y0,|E  
n = nLen; P~$< X  
} 'A{h iY  
catch(IOException e) R'K/t|MC  
{ eBr4O i  
e.printStackTrace (); F#r#}.B='U  
} X~U >LLr  
`x8B n"  
8QgA@y"  
return n; xh9qg0d  
} I+?hG6NM  
rs8\)\z  
B&KL2&Z~Pq  
} {ShgJ ;! Q  
f4t.f*#  
Un=a fX?j  
/* +Ghi}v  
**SiteInfoBean.java r#876.JK  
*/ y=N"=Z  
package NetFox; Q4'C;<\@(Q  
dDcZ!rRaL@  
kEN#u  
public class SiteInfoBean { %CH6lY=lI  
]?l{j  
0%C^8%(x  
private String sSiteURL; //Site's URL C 0C0GqN,  
private String sFilePath; //Saved File's Path H'g?llh1J  
private String sFileName; //Saved File's Name 4cgIEw[6  
private int nSplitter; //Count of Splited Downloading File 0irr7Y  
=]>%t]  
4*H"Z(HP  
public SiteInfoBean() >%%=0!,yX  
{//nSplitter的缺省值为5 -$k>F#  
//default value of nSplitter is 5 xF8S*,#,*  
this("","","",5); I}0_nge  
} J1F{v)T '?  
j'rS&BI G  
m2bDHQ+  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6qp5Xt+  
{ I44s(G1j l  
sSiteURL= sURL; wz(K*FP  
sFilePath = sPath; 440FhD Mj  
sFileName = sName; pWaPC /,g  
this.nSplitter = nSpiltter; /p`&;/V|  
Fz"ff4Bx [  
f05d ;  
} zmFws-+A  
~ 9M!)\~  
;IP~Tb]&  
public String getSSiteURL() D!3{gV#  
{ &w\ I<J`T  
return sSiteURL; yXfMzG  
} P'[<A Z  
m#@_8_ M  
hl/itSl$  
public void setSSiteURL(String value) "ED8z|]j  
{ :{}_|]>K  
sSiteURL = value; .KA V)So"  
} EQ >t[ &  
M}FWBs'*|  
Bq}x9C&<  
public String getSFilePath() =Viy^ieN$  
{ V|?WF&  
return sFilePath; mUXk9X%n  
} sg?@qc=g  
ZXXiL#^  
>M4"|W U_  
public void setSFilePath(String value) =4NqjSH  
{ ;bjnL>eW  
sFilePath = value; .]t5q%}j  
} /=T"=bP#/  
L]-w;ll-  
;iX<`re~  
public String getSFileName() YMB~[]$V<  
{ 3)E(RyQA3  
return sFileName; Y`li> .\  
} >)Dhi+D  
,;iA2  
JeQ[qQ  
public void setSFileName(String value) s-D?)  
{ >;lKLGJrd>  
sFileName = value; \Ow,CUd  
} ~<O,Vs_C/  
,b.n{91[]x  
wh6&>m#r  
public int getNSplitter() GW m4~]0E  
{ _w u*M  
return nSplitter; P[i\e7mR  
} 2P}I'4C-  
f1cl';  
`BT^a =5  
public void setNSplitter(int nCount)  )U98  
{ aqL<v94wX  
nSplitter = nCount; YKx 1NC  
} Jt=>-Spj  
} g9V.13k  
5' \)`  
Y3o Mh,  
/* n<R \w''x  
**Utility.java lX;mhJj!  
*/ MUwVG>b8J~  
package NetFox; AzjMv6N   
h}6_ybmZ  
tgN92Q.i6T  
public class Utility { #5{sglC"|F  
j%xBo:  
YmDn+VIg  
public Utility() H@W0gK(cS;  
{ V5s& hZZYa  
]P3[.$z  
 P\(30  
} Lk nVqZ|k  
rm|7 [mK  
//线程睡眠 %V_eJC""?  
public static void sleep(int nSecond) mw+j|{[  
{ jT^!J+?6K+  
try{ 0xP:9rm  
Thread.sleep(nSecond); {hd-w4"115  
} OmNn,PCl8  
catch(Exception e) -Enbcz(B  
{ I~RcOiL)  
e.printStackTrace (); Phlk1*1n  
} \(u@F<s-  
} mQ,{=C=D  
Xp^$ E6YFy  
//日志 :~-i&KNk  
public static void log(String sMsg) Lz6*H1~   
{ 2oB?Dn  
System.err.println(sMsg); <7RfBR.9  
} <.$,`m,  
rw*M&qg!z  
t-EV h~D1p  
public static void log(int sMsg) B$7[8h  
{ VM;g +RRq  
System.err.println(sMsg); e6m1NH4,  
} f\'G`4e  
} F@^N|;_2  
PP4d?+;V  
5"2@NL  
/* =1Sy@MbH3  
**TestMethod.java !E0fGh  
*/ MPG+B/P&  
package NetFox; g RU-g  
gV`S%   
$i%HDt|  
public class TestMethod { m3"c (L`B  
dqz1xQ1  
Sj1r s#@1  
public TestMethod() swt\Ru6,  
{ ///xx/weblogic60b2_win.exe 4k*qVOBa6R  
try{ %mmxA6I  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); gix>DHq$k  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @Yarz1  
SiteFileFetch fileFetch = new SiteFileFetch(bean); `skH-lk,  
fileFetch.start(); %IU4\ZY>  
} 5~yQ>h  
catch(Exception e){e.printStackTrace ();} d'q&Lq  
"c EvFY  
8J^d7uC  
} +7^w9G  
i&pMF O  
Ej5^Y ?-6  
public static void main(String[] args) #:I^&~:  
{ N.vG]%1"  
new TestMethod(); d3(+ztmG!  
} 2{gwY85:  
} 2D_6  
点击下载更多相关资料
评价一下你浏览此帖子的感受

精彩

感动

搞笑

开心

愤怒

无聊

灌水
描述
快速回复

您目前还是游客,请 登录注册
如果您提交过一次失败了,可以用”恢复数据”来恢复帖子内容
认证码:
验证问题:
10+5=?,请输入中文答案:十五