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http断点续传简单实现(java)

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/* f1mHN7hxW  
**SiteFileFetch.java A\z`c e!  
*/ -4w%Iy  
package NetFox; rK1-Mu  
import java.io.*; =m7H)z)i*J  
import java.net.*; _%y4q%#  
k[\a)WcY8  
a2`%gh W3  
public class SiteFileFetch extends Thread { ]H ~Y7\N-v  
!9;)N,  
=O!|IAe#  
SiteInfoBean siteInfoBean = null; //文件信息Bean @x1 %)1  
long[] nStartPos; //开始位置 !Xj#@e  
long[] nEndPos; //结束位置 qI%&ay"/  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 .2.qR,"j  
long nFileLength; //文件长度 u-JpI-8h  
boolean bFirst = true; //是否第一次取文件 S]^`woD  
boolean bStop = false; //停止标志 { p;shs5  
File tmpFile; //文件下载的临时信息 h >-'-Hx+  
DataOutputStream output; //输出到文件的输出流 ~i ,"87$[  
]f8L:=c  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) lCJ6Ur;  
public SiteFileFetch(SiteInfoBean bean) throws IOException %@?A_jS  
{ TVaA>]Fv  
siteInfoBean = bean; {$d<1y^  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); y6-XHeU  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); X32C}4-B  
if(tmpFile.exists ()) gl{B=NN  
{ a 7#J2r  
bFirst = false; \'Ssn(s  
read_nPos(); wN97_Y=`n  
} ^C/  
else ]kD"&&HV  
{ jV O{$j  
nStartPos = new long[bean.getNSplitter()]; dRW$T5dac  
nEndPos = new long[bean.getNSplitter()]; nv0#~UgE#a  
} Y- )x Tn  
${I*nh>=  
u.,Q4u|!  
.@#A|fgv  
} Vi?q>:E:  
z.36;yT/  
kJ{+M]pW  
public void run() %Jp|z? [/  
{ vDFGd-S  
//获得文件长度 _{4^|{>Pv  
//分割文件 fBhoGA{=g  
//实例FileSplitterFetch !m;H@KR{  
//启动FileSplitterFetch线程 :>+\17tx  
//等待子线程返回 29&bbfU  
try{ iafE5b)  
if(bFirst) I9?Ec6a_  
{ \]uV!)V5B  
nFileLength = getFileSize(); pTJX""C  
if(nFileLength == -1) MHU74//fe  
{ E5</h"1  
System.err.println("File Length is not known!"); M5g\s;y;  
} Z hd#:d  
else if(nFileLength == -2) MSw$_d  
{ %Ip*Kq-  
System.err.println("File is not access!"); GbI-SbE  
} #wY0D_3@1  
else _%/}>L>-`8  
{ .ubE2X[][  
for(int i=0;i<nStartPos.length;i++) kLj$@E`4  
{ 7fHc[,  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); W3H+.E  
} HCWNo  
for(int i=0;i<nEndPos.length-1;i++) Y}s@WJ  
{ ea'&xs#GK  
nEndPos = nStartPos[i+1]; H[ m <RaG8  
} M|,mr~rRG  
nEndPos[nEndPos.length-1] = nFileLength; `=UWqb(K_  
} @-HG`c ct  
} -' g*^  
a u7.4ln>Y  
v&a4^s  
//启动子线程 z^<L(/rg9"  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bN$r k|  
for(int i=0;i<nStartPos.length;i++) \$sjrqKnu  
{ +Q$h ]^>~  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Wp)*Mbq@  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Lfog {Vzs  
nStartPos,nEndPos,i); T4)fOu3]  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nUS| sh  
fileSplitterFetch.start(); !3X0FNGq  
} D^ Jk@<*  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /FD5 G7ES  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1);  -I.d}[  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1)m@?CaI`  
nEndPos = " + nFileLength); TaE~s  
// fileSplitterFetch[nPos.length-1].start(); lVOu)q@l7g  
F$BbYf2i  
V#REjsf,t-  
//等待子线程结束 Zf$Np50@(  
//int count = 0; qz?mh4Oh  
//是否结束while循环 M(x$xAiD  
boolean breakWhile = false; rf~Y6U?7  
8N&+7FK  
1u3, '8F  
while(!bStop) L){iA-k;Ec  
{ \K`L3*cBKK  
write_nPos(); 5GA C`}}  
Utility.sleep(500); v6.t{6zYgY  
breakWhile = true; M?m,EQh.  
s\!>"J bAQ  
3?2 FP|G8  
for(int i=0;i<nStartPos.length;i++) oND@:>QBF  
{ I[)%,jd  
if(!fileSplitterFetch.bDownOver) mKr h[nA  
{ h2ytS^  
breakWhile = false; &xRo^iV?  
break; Q></`QWpoB  
} L:XC  
} wO?{?+I`q  
if(breakWhile) "&/-N[is  
break; c\a_VRN>r  
'5&s=M_  
8NyJc"T<.  
//count++; [ ol9|sdu  
//if(count>4) kuyjnSo9i  
// siteStop(); jC bV,0)^  
} y@0E[/O  
BauU{:Sh  
C8 \5A8c  
System.err.println("文件下载结束!"); DL$@?.?I  
} :#@= B]  
catch(Exception e){e.printStackTrace ();} 7}M2bH} \K  
} PDs@?nz,  
$Y69@s%f  
;)N>t\v  
//获得文件长度 '>r7V  
public long getFileSize() EoK~S\dS  
{ 94B\5I}  
int nFileLength = -1; hzkcP  
try{ UQ{L{H   
URL url = new URL(siteInfoBean.getSSiteURL()); ggJO:$?$L  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *S2ypzwRZ,  
httpConnection.setRequestProperty("User-Agent","NetFox"); [Xb@Wh:yG  
9eH$XYy  
uj :%#u  
int responseCode=httpConnection.getResponseCode(); BNL;Biy t7  
if(responseCode>=400) uEX!xx?Q#  
{ g$b<1:8  
processErrorCode(responseCode); dCRyOid$  
return -2; //-2 represent access is error /~zai}  
} 8F._9U-EN  
&Z`#cMR{H  
hCC<?5q  
String sHeader; #B4%|v;`E?  
T}8Y6N<\m  
6i1LjLB  
for(int i=1;;i++) '&\kxNglJ  
{ |`.([2  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 30SW\@  
//Utility.log(in.readLine()); Ytl4kaYS  
sHeader=httpConnection.getHeaderFieldKey(i); EOCN&_Z;  
if(sHeader!=null) 6oGYnu;UZ  
{ Uu`9 "  
if(sHeader.equals("Content-Length")) Mnscb  
{ zG(\+4GE!  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2nR[Xh?L  
break; :Of^xj>A  
} YJ\Xj56gv  
} /Njd[= B  
else g*_cP U0~m  
break; VIv&ofyAR  
} <ZNzVnVA  
} RS8Hf~0G  
catch(IOException e){e.printStackTrace ();} ME*LH r,  
catch(Exception e){e.printStackTrace ();} >k (C  
N<XNTf  
E"5*Ei)^3  
Utility.log(nFileLength); MRdduPrM%$  
,%M$0poKM  
mWsI}2  
return nFileLength; [k/@E+;  
} )r jiY%F$  
2+e}*&iQpp  
n CdR EXw  
//保存下载信息(文件指针位置) V=o t-1,j7  
private void write_nPos() h-` }L=  
{ ]?!mS[X  
try{ a ?)NC  
output = new DataOutputStream(new FileOutputStream(tmpFile)); AJF#Aw `o  
output.writeInt(nStartPos.length); 2Eu`u!jhx  
for(int i=0;i<nStartPos.length;i++) uC(V  
{ %-1O.Q|f  
// output.writeLong(nPos); Y2~nBb  
output.writeLong(fileSplitterFetch.nStartPos); gcl5jB5)>  
output.writeLong(fileSplitterFetch.nEndPos); @X#F3;  
} }f6HYU  
output.close(); oYH^_V  
} ,Ge"anO  
catch(IOException e){e.printStackTrace ();} .nx2";oi  
catch(Exception e){e.printStackTrace ();} ` 2V19 s]  
} oYm[V<nIl  
nH[yJGZYSA  
pSdI/Vj'=  
//读取保存的下载信息(文件指针位置) H _zo1AW  
private void read_nPos() D=-SO +  
{ X:nN0p #  
try{ "W955?4m  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); W *),y:  
int nCount = input.readInt(); <^5Z:n!q  
nStartPos = new long[nCount]; t*1fLumXR  
nEndPos = new long[nCount]; 7`DBS^O]dG  
for(int i=0;i<nStartPos.length;i++) $#9;)8J  
{ .uMn0PE   
nStartPos = input.readLong(); o<pf#tifv  
nEndPos = input.readLong();  +|n*b  
} JR@`2YP-  
input.close(); hG12ZZD  
} EVsC >rz  
catch(IOException e){e.printStackTrace ();} PgF* 1  
catch(Exception e){e.printStackTrace ();} Lh!J >  
} YUtC.TR1  
CVL3VT1j0  
T[UN@^DP(  
private void processErrorCode(int nErrorCode) svcK?^ HTe  
{ 5YeM%%-S  
System.err.println("Error Code : " + nErrorCode); I 8`VNA&b  
} 3z{?_;bR  
1W^t aJH]  
i@"@9n~  
//停止文件下载 M_/7D|xl/T  
public void siteStop() QI'Oz{vE  
{ "K6&dk jY  
bStop = true; :V RNs  
for(int i=0;i<nStartPos.length;i++) 4.[^\N  
fileSplitterFetch.splitterStop(); ,St#Vla  
qNB<T('  
7:plQ !7^  
} $P^q!H4D  
} S2sQOM@  
//负责部分文件的抓取 N4F.Y"R$(  
**FileSplitterFetch.java 6xTuNE1  
*/ MyJ%`@+1  
package NetFox; {?}E^5Z*g  
0zmE>/O+  
Z>:NPZODf  
import java.io.*; Vc&! OE  
import java.net.*; p6>Svcc  
8lvV4yb  
/Kql>$I  
public class FileSplitterFetch extends Thread { ls\WXCH  
=.Pw`.  
S"NqM[W  
String sURL; //File URL I_} SB|  
long nStartPos; //File Snippet Start Position CkOz  
long nEndPos; //File Snippet End Position c|e~BQdRw  
int nThreadID; //Thread's ID [%y';`( x  
boolean bDownOver = false; //Downing is over [1g8*j~L  
boolean bStop = false; //Stop identical zy/@ WFPE  
FileAccessI fileAccessI = null; //File Access interface a*lh)l<KV  
pjKWtY@=X  
`VA"vwz  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =Y{(%sn  
{ <\r T%f}3^  
this.sURL = sURL; UZ\u;/}  
this.nStartPos = nStart; \A 2r]  
this.nEndPos = nEnd; K[YI4pt7  
nThreadID = id; kCWV r  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 YxYH2*q@  
} >JHryS.j$4  
j4gF;-m<  
N.,X<G.H  
public void run() `i3NG1 v0  
{ q9KHmhUD  
while(nStartPos < nEndPos && !bStop) fInb[  
{ HVR /7&g  
ry`Ho8N  
x -WmMfcz&  
try{ ak$f"py x  
URL url = new URL(sURL); X`kk]8 =  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lA| 5E?  
httpConnection.setRequestProperty("User-Agent","NetFox"); oK6tTK  
String sProperty = "bytes="+nStartPos+"-"; ?GKb7Oj  
httpConnection.setRequestProperty("RANGE",sProperty); >)fi^  
Utility.log(sProperty); q/4J.j L  
9UdM`v)(  
rK'L6o  
InputStream input = httpConnection.getInputStream(); EH+"~-v)ae  
//logResponseHead(httpConnection); gX@HO|.t  
>?2M }TV3  
h5*JkRm  
byte[] b = new byte[1024]; ysQ_[ ]/  
int nRead; RIWxs Zt  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ugdQAg  
{ vOn`/5-  
nStartPos += fileAccessI.write(b,0,nRead); 6 a(yp3  
//if(nThreadID == 1) dI.WK@W'o  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w1Nm&}V  
} g0xuxK;9c  
"h{q#~s  
kj#?whK6~  
Utility.log("Thread " + nThreadID + " is over!"); .F4>p=r  
bDownOver = true; GFj{K  
//nPos = fileAccessI.write (b,0,nRead); =)0,#9k U]  
} }NHaCG[,  
catch(Exception e){e.printStackTrace ();} hci6P>h<ia  
} ? &o2st  
} pA'4|ffwe  
zqimR#u  
cvn@/qBq*t  
//打印回应的头信息 |HiE@  
public void logResponseHead(HttpURLConnection con) y`Wty@  
{ >:74%D0UF  
for(int i=1;;i++) [owWiN4`s  
{ Ci@o|Y }tP  
String header=con.getHeaderFieldKey(i); MK%9:wZ  
if(header!=null) ~qiJR`Jj  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }*M6x;t  
Utility.log(header+" : "+con.getHeaderField(header)); $t$ShT)  
else y;35WtDVb  
break; [<lHCQXJ/  
} 5V?& 8GTe  
} {% rA1g  
0IsPIi"7  
.?8;qA  
public void splitterStop() wcrCEX=I>{  
{ ,;EIh}  
bStop = true;  :|>h7v  
} G)EU_UE 9  
8zZvht*  
3@etRd;]Kr  
} \\iQEy<i  
&PR5q 7  
rN<0 R`4sE  
/* &|s0P   
**FileAccess.java R6` WN  
*//文件访问(定位,写) iOd&B B6  
package NetFox; <wk!hTm W  
import java.io.*; qmkAg }2  
;,hwZZA  
!y\'EW3|G  
public class FileAccessI implements Serializable{ 4`4kfiS$  
Tm~" IB*  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \o z#l'z  
RandomAccessFile oSavedFile; iFd+2S%  
long nPos; TJ10s%,V  
8H%;WU9-  
iN bIp"W  
public FileAccessI() throws IOException }5ret  
{ Tr_w]'  
this("",0); !{ y@od@T  
} tIWmp30S  
xs{3pkTYD  
]N~2 .h  
public FileAccessI(String sName,long nPos) throws IOException )1]ZtU  
{ 2i)^ !c  
oSavedFile = new RandomAccessFile(sName,"rw"); G"r1+#  
this.nPos = nPos; _~'=C#XI)  
oSavedFile.seek(nPos); hCi60%g/n  
} _zR+i]9   
+Zb;Vn4  
(of#(I[m7  
public synchronized int write(byte[] b,int nStart,int nLen) eQ$Y0qH1E  
{ !44/sr'  
int n = -1; 6LvW?z(J  
try{ Lm iOhx  
oSavedFile.write(b,nStart,nLen); 0CZ :Bo[3  
n = nLen; g{7.r-uu  
} R4[N:~Z$|  
catch(IOException e) oI?3<M^  
{ S(k3 `;K  
e.printStackTrace (); ^%d\qd`   
} YX!{P=Ua  
n7zm>&  
B al`y  
return n; r)Ma3FL0;  
} |-fg j'  
/fKx} }g)  
5[8xV%>;  
} 0CWvYC%e  
6gL #C&  
C(eTR1  
/* {AhthR%(1  
**SiteInfoBean.java  U'k*_g  
*/ 6]&OrS[  
package NetFox; .6ylZ  
x!?u^  
f&=AA@jLv  
public class SiteInfoBean { XPavReGf  
h&M{]E9=  
h}>"j%I  
private String sSiteURL; //Site's URL Z&G+bdA>,  
private String sFilePath; //Saved File's Path |hKDvH  
private String sFileName; //Saved File's Name 7!$Q;A  
private int nSplitter; //Count of Splited Downloading File y8d]9sX{  
[meO[otb  
;o 6lf_  
public SiteInfoBean() #oS<E1  
{//nSplitter的缺省值为5 ;(b9#b.  
//default value of nSplitter is 5 KKb,d0T[  
this("","","",5); IY_iB*T3jt  
} ]P9l jwR  
B |5]Jm]  
kGH}[w  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) s%vis{2  
{ zv|2:4H  
sSiteURL= sURL; l^! ?@Kg,z  
sFilePath = sPath; 5us:adm[pD  
sFileName = sName; Z|&MKG24  
this.nSplitter = nSpiltter; `vU%*g&R  
V)3KS-  
^\hG"5#  
} \q>bs|2  
DRSr%d  
RaO-H  
public String getSSiteURL() MOQ6 :  
{ |-b#9JQ[A  
return sSiteURL; 4`lLf  
} [xbSYu,&  
Bm:98? [  
3RigzT3  
public void setSSiteURL(String value) 59 h]UX=  
{ Ka'=o?'B5  
sSiteURL = value; C0sX gM  
} Vouvr<43o  
g!|=%(G=  
p99 ]  
public String getSFilePath() <3oWEm  
{ ?3/qz(bM  
return sFilePath; Je';9(ZK  
} gl~ecc  
 Z< 1  
rbul8(1h  
public void setSFilePath(String value) Z@yW bjE7Z  
{ aJSO4W)P  
sFilePath = value; cA&9e<  
} L s G\OG  
kAKK bmE  
d .[8c=$  
public String getSFileName() _H9 MwJ  
{ d|jNf</`  
return sFileName; > ;jZa  
} 3(``#7  
`b?R#:G  
Av$]|b  
public void setSFileName(String value) Vk` h2BV  
{ mJ<=n?{Z  
sFileName = value; zp6C3RG(  
} af6M,{F  
|e=,oV"  
ay4 %  
public int getNSplitter() \Yy$MLs  
{ ['b}QW@Fx  
return nSplitter; Z/G ev"p  
} [Hx0`Nc K  
tCw<Ip  
%3s1z<;R[S  
public void setNSplitter(int nCount) *}Xf!"I#]N  
{ :Oy%a'w   
nSplitter = nCount; f<-Jg  
} pLl(iNf]  
} I"xo*}  
BIH-"vTy  
O6@j &*jS  
/* ,1hxw<sNR  
**Utility.java f@6QvkIa  
*/ e*sfPHt  
package NetFox; HsxVZ.dS  
GmK^}=frj  
+|*IZ:w)  
public class Utility { a a<8,;  
0`Kj 25  
)z>|4@,  
public Utility() Qo>b*Ku;  
{ @<,X0S  
.28<tEf  
YP 6` L  
} -<6\1J  
} j<)L,  
//线程睡眠 ~cWAl,(B<F  
public static void sleep(int nSecond) %Celc#v  
{  Ii6<b6-  
try{ AWcLUe{  
Thread.sleep(nSecond); 5sdn[Tt##  
} P)"noG_'i  
catch(Exception e) C^s^D:   
{ {ba q+  
e.printStackTrace (); =NpYFKmMhV  
} FW.7'7G@n  
} z Eq GD2"  
57aXQ8u{  
//日志 K)6rY(x >  
public static void log(String sMsg) m )8BgCy  
{ v0ujdp,B  
System.err.println(sMsg);  vx\r!]  
} ih)zG  
$Y;U[_l#  
v/@^Q1 G/:  
public static void log(int sMsg) ?yZ+D z\  
{ -N6f1>}pE  
System.err.println(sMsg); ; a/X<  
} %) /s;Q,  
} t9nqu!);  
EJj.1/]|r  
5]~'_V  
/* -M~8{buxv  
**TestMethod.java ,aOl_o -&  
*/ _> f`!PlB|  
package NetFox; a Ve'ry  
>~#yu&*D  
B`YTl~4  
public class TestMethod { LU \i0|i|  
#r$cyV!k  
I?]ohG K  
public TestMethod() @#<D ^"  
{ ///xx/weblogic60b2_win.exe Q`~jw>x  
try{ ^pxX]G]  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7jxslI&F  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?:pP8/y  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~Uj=^leYO  
fileFetch.start(); ;m0~L=w  
} :Hn6b$Vy8  
catch(Exception e){e.printStackTrace ();} :uP,f<=)K  
tankR9(o  
[O$Wa:< 0x  
} VdPtPq1  
?OId\'q  
O $LfuL  
public static void main(String[] args) rr+|Zt Y  
{ V n7*JS  
new TestMethod(); NYt&@Z}]  
} Sw:7pByjI  
} &[_g6OL  
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