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http断点续传简单实现(java)

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/* ) jH`lY)1  
**SiteFileFetch.java >> "gb/x,  
*/ V0v,s^\H  
package NetFox; Kc?4q=7q  
import java.io.*; 7M~sol[*  
import java.net.*; w^ut,`yW R  
z,4mg6gt  
<|4$T H^ t  
public class SiteFileFetch extends Thread { R8k4?_W?T  
o^vX\a?`u  
gr*CN<  
SiteInfoBean siteInfoBean = null; //文件信息Bean q6)fP4MQ]  
long[] nStartPos; //开始位置 KF00=HE|]  
long[] nEndPos; //结束位置 X0u,QSt' O  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 {?eUAB<  
long nFileLength; //文件长度 1*9.K'  
boolean bFirst = true; //是否第一次取文件 ?}Zt&(#  
boolean bStop = false; //停止标志 4lB??`UN  
File tmpFile; //文件下载的临时信息 ?:J_+? {E  
DataOutputStream output; //输出到文件的输出流 A vq+s.h  
8Rwk o6x  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) d(o=)!p  
public SiteFileFetch(SiteInfoBean bean) throws IOException o]4\Geg$  
{ Si>38vCJ*  
siteInfoBean = bean; )rK2%\Z  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); :R,M Y"(  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); iCF},W+  
if(tmpFile.exists ()) Sy|GM~  
{ ^~;ia7V&2  
bFirst = false; ? +L,  
read_nPos(); = 'NV3by  
} IibrZ/n6  
else Q2VF+g,  
{ RyJy%| \-S  
nStartPos = new long[bean.getNSplitter()]; HCs^?s8Pp  
nEndPos = new long[bean.getNSplitter()]; `SFeln{1B  
} cdt9hH`Cd  
Zk%@GOu\  
din,yHu~  
D#b*M)X"  
} z}ar$}T  
H\R a*EO~j  
t1adS:)s  
public void run() ixu*@{<Z(  
{ d fj23+  
//获得文件长度 b$,Hlh,^  
//分割文件 z6iKIw $  
//实例FileSplitterFetch 172G  
//启动FileSplitterFetch线程 cRVL1ne  
//等待子线程返回 K:a8}w>Up  
try{ 1IA1;  
if(bFirst) D=-}&w_T"  
{ @gD) pH  
nFileLength = getFileSize(); tp] 5[U  
if(nFileLength == -1) Q v9q~l  
{ f1MRmp-f'  
System.err.println("File Length is not known!"); HrBJi  
} = ^NvUrK  
else if(nFileLength == -2) 'q-q4 QCB  
{ }tW-l*\U  
System.err.println("File is not access!"); s$R /!,c  
} }`B .(3n  
else eWcqf/4?"  
{ bQt:=>  
for(int i=0;i<nStartPos.length;i++) J:m/s9r  
{ {Yj5Mj|#  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); <: v+<)K  
} 5l6/5  
for(int i=0;i<nEndPos.length-1;i++) *y*tI}  
{ 8}  B  
nEndPos = nStartPos[i+1]; \Fz9O-jb4  
} v|%41xOsr  
nEndPos[nEndPos.length-1] = nFileLength; /| v.A\ :  
} y|5s  
} r(>S  
6{y7e L3!  
+ Q-b}  
//启动子线程 z qeQ  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Tc6cBe,  
for(int i=0;i<nStartPos.length;i++) ?G,4N<]Nu  
{ V)^Xz8H_  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d05xn7%!{  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =Zq6iMD  
nStartPos,nEndPos,i); :jiuu@<  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f$o^Xu  
fileSplitterFetch.start(); +` Md5.w  
} kamQZzPe  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S<i$0p8J;  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >v:ex(y0  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &h334N|4{  
nEndPos = " + nFileLength); KZppQ0  
// fileSplitterFetch[nPos.length-1].start(); h6h6B.\ Ld  
V?u#WJy/  
4[gmA  
//等待子线程结束 UBaXS_c\  
//int count = 0; QL/KY G  
//是否结束while循环 NIV}hf YF  
boolean breakWhile = false; ${ {4L ?7  
3B1\-ry1M  
24jf`1XFW  
while(!bStop) 9{u8fDm!  
{ tIuM9D{P  
write_nPos(); pbVL|\oB}  
Utility.sleep(500); L`+[mX&2B  
breakWhile = true; op6]"ZV-C  
'}Fe&%  
%B%_[<B  
for(int i=0;i<nStartPos.length;i++) >fBPVu\PA  
{ ppAbG,7  
if(!fileSplitterFetch.bDownOver) >yO/p(/;jR  
{ 6 4_}"fU  
breakWhile = false; H/D=$)3op  
break; -b-a21,m>  
} \o>-L\`O  
} LDt6<D8,Q  
if(breakWhile) |qNe_)  
break; 7Nq< o5  
mfr aw2H  
$BwWQ?lp  
//count++; ea 3w  
//if(count>4) >XgoN\w  
// siteStop(); cE\w6uBR1  
} E|@C:ghG  
fd)8lK[KJ"  
?qjdmB|w  
System.err.println("文件下载结束!"); z$1RD)TQB  
} ,>j3zjf^  
catch(Exception e){e.printStackTrace ();} j 3<Ci {3  
} =3bk=vy  
^#_gk uyd!  
k1B ](@xt  
//获得文件长度 gT)(RS`_)  
public long getFileSize() `^)`J  
{ w  S  
int nFileLength = -1; K"!rj.Da  
try{ @M'k/jl  
URL url = new URL(siteInfoBean.getSSiteURL()); u+)!C*ho  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bQaRl=:[:  
httpConnection.setRequestProperty("User-Agent","NetFox"); )M8d\]  
iJTG +gx  
+Br<;sW  
int responseCode=httpConnection.getResponseCode(); u3h(EAH>  
if(responseCode>=400) P y'BMk  
{ %xgP*%Sv2  
processErrorCode(responseCode); ~^F]t$rz  
return -2; //-2 represent access is error c~T {;  
} rc=E%Qv%?  
g#I`P&  
LK h=jB^bT  
String sHeader; ,+i^]yF3j  
Zo=,!@q(  
-h8mJ D%Oi  
for(int i=1;;i++) c&D+=   
{ 01n!T2;yW}  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +R~]5Rxd  
//Utility.log(in.readLine()); ?1\5X<|,  
sHeader=httpConnection.getHeaderFieldKey(i); h[(YH ;Y  
if(sHeader!=null) Hca(2 ]T-  
{ _c]}m3/  
if(sHeader.equals("Content-Length")) 2f(`HSC'  
{ i;HXz`vT7  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); A+/Lt>+AS  
break; xM_#FxJb  
} r`"_D%kc  
} 6C$+D  
else ?c.\\2>|F  
break; s.z)l$  
} ,88B@a  
}  U#f*  
catch(IOException e){e.printStackTrace ();} '&CZ%&(Gw  
catch(Exception e){e.printStackTrace ();} h#zm+([B*  
m0G"Aj  
)=)N9CRy  
Utility.log(nFileLength); ~criZI/  
l&H-<Z.8m  
],c0nz^%BR  
return nFileLength; r,eH7&P9{  
} }Z <I%GT  
"|6(.S+o  
yK{P%oh)  
//保存下载信息(文件指针位置) +9HU&gQ3  
private void write_nPos() !KV!Tkx h  
{ 6F^/k,(k4  
try{ Pr>$m{ Z  
output = new DataOutputStream(new FileOutputStream(tmpFile)); $I5|rB/4?  
output.writeInt(nStartPos.length); ^ iu)vED  
for(int i=0;i<nStartPos.length;i++) 3g7]$}  
{ 0+0 Y$;<  
// output.writeLong(nPos); $ (&uaDYv  
output.writeLong(fileSplitterFetch.nStartPos); d^'_H>x  
output.writeLong(fileSplitterFetch.nEndPos); !jP[=  
} 42 `Uq[5Y  
output.close(); r%: :q^b3  
} /:!sn-(  
catch(IOException e){e.printStackTrace ();} ccv  
catch(Exception e){e.printStackTrace ();} 9Zx| L/\  
} `c:r`Oi?  
u9_? c G-  
d Np%=gIj  
//读取保存的下载信息(文件指针位置) H~[q<ybxr  
private void read_nPos() ~ &/Nl_#  
{ Fmn_fW6  
try{ ;zqxDl_  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %~eu&\os  
int nCount = input.readInt(); , wk}[MF  
nStartPos = new long[nCount]; hj=n;,a9  
nEndPos = new long[nCount]; V xN!Ki=  
for(int i=0;i<nStartPos.length;i++) zRh)q,Dt  
{ m<Gd 6V5  
nStartPos = input.readLong(); s2sJJdN  
nEndPos = input.readLong(); O-AC$C[d  
} + fvVora  
input.close(); , -])[u  
} 6heK8*.T  
catch(IOException e){e.printStackTrace ();} =>*}qen  
catch(Exception e){e.printStackTrace ();} F, =WfM\  
} } %3;j5 ;6  
o<|u4r={s  
axG%@5  
private void processErrorCode(int nErrorCode) }T%E;m-  
{ *"|f!t  
System.err.println("Error Code : " + nErrorCode); :t;\`gQoS  
} J?p|Vy|9  
`34+~;;Jh  
TPJuS)TU9  
//停止文件下载 B_!S\?}$  
public void siteStop() jcePSps]  
{ `[=/f=Q}  
bStop = true; jxK `ShW=  
for(int i=0;i<nStartPos.length;i++) fN`Prs A  
fileSplitterFetch.splitterStop(); s$^ 2Cuhv  
rl"yE=  
1\jj3Y'i'  
} D<Z\6)|%I  
} ~ LH).\V  
//负责部分文件的抓取 g6q[ I8  
**FileSplitterFetch.java wh]v{Fi'  
*/ Kt#X'!9/<  
package NetFox; ]{-ib:f~  
5IG#-Q(6sp  
<l)I% 1T_c  
import java.io.*; N[=R$1\Z  
import java.net.*; AQ-R^kT  
Xp^71A?>  
P; =,Q$e8  
public class FileSplitterFetch extends Thread { S?H qrf7<  
5X`m.lhUc  
M/6q ^*  
String sURL; //File URL _t7aOH  
long nStartPos; //File Snippet Start Position ds+0y;vc  
long nEndPos; //File Snippet End Position n\scOM)3  
int nThreadID; //Thread's ID gdBH\K(\  
boolean bDownOver = false; //Downing is over &-.2P!t  
boolean bStop = false; //Stop identical CJLfpvV  
FileAccessI fileAccessI = null; //File Access interface g<4@5OQKu  
xirZ.wjW  
~<_P jV  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException u_)'}  
{ ;#2yF34gv  
this.sURL = sURL; NSh~O!pX  
this.nStartPos = nStart; "qY_O/Eg]]  
this.nEndPos = nEnd; *Q3q(rdrp  
nThreadID = id; _K>YB>W}7  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;x=0+0JD  
} "IdN*K  
\R#OJ=F  
Pu]Pp`SP  
public void run() rcMSso2  
{ [tz}H&  
while(nStartPos < nEndPos && !bStop) i\k>2df  
{ I_h&35^t  
*+cW)klm  
8<g9 ~L  
try{ AtlUxFX0S  
URL url = new URL(sURL); &p^8zEs  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &qFy$`"  
httpConnection.setRequestProperty("User-Agent","NetFox"); v+`gQXJ"G  
String sProperty = "bytes="+nStartPos+"-"; M,9f}V)  
httpConnection.setRequestProperty("RANGE",sProperty); arj?U=zy  
Utility.log(sProperty); [Gb8o'  
[[0u|`T/  
eN ]9=Y~-K  
InputStream input = httpConnection.getInputStream(); PeB7Q=d)K1  
//logResponseHead(httpConnection); fnO>v/&B  
GZqy.AE,  
>*goDtTjp  
byte[] b = new byte[1024]; V> @+&q  
int nRead; ZC:7N{a  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _0e;&2')  
{ 8d"Ff  
nStartPos += fileAccessI.write(b,0,nRead); =ET|h}I  
//if(nThreadID == 1) ZncJ  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); },G5!3  
} iyf vcKO  
.qk_m-o  
-eoXaP{[  
Utility.log("Thread " + nThreadID + " is over!"); jAb R[QR1%  
bDownOver = true; EAXbbcV  
//nPos = fileAccessI.write (b,0,nRead); dJD8c 2G  
} OB5`a,5dI  
catch(Exception e){e.printStackTrace ();} BO)Q$*G~JD  
} .:=G=v=1  
} "_T8Km008  
i"o %Gc  
LL^WeD_Y  
//打印回应的头信息 ]728x["(19  
public void logResponseHead(HttpURLConnection con) i_6 Y6  
{ f& >[$zh  
for(int i=1;;i++) #Z]l4d3{T  
{ `8D}\w<eI  
String header=con.getHeaderFieldKey(i); _B5v&# h(.  
if(header!=null) 0'0GAh2  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); bs=x>F  
Utility.log(header+" : "+con.getHeaderField(header)); 8C>\!lW"  
else {:0TiOP5x  
break; +Q+>{HK  
} E1-BB  
} 0B?t:XU,  
ij+)U`  
Q9h;`G 7t  
public void splitterStop() DqGm  
{ &;]KntxB  
bStop = true; XIJW$CY  
} U^.kp#x#  
2Ub!wee  
HJeZm  
} rsgTd\b  
%DR8M\d1~H  
2/m4|  
/* .>Fy ]Cqoh  
**FileAccess.java )D"E]  
*//文件访问(定位,写) E\Et,l#|LY  
package NetFox; xaG( 3  
import java.io.*; 7 I`8r2H  
5b5Hc Inu  
4V9S~^v|  
public class FileAccessI implements Serializable{ VHihC]ks,  
lOuO~`,J  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 70BLd(?  
RandomAccessFile oSavedFile; n3Q Rn^  
long nPos; _ ^ny(zy(  
EYD24  
;S.o` z1GI  
public FileAccessI() throws IOException \7U'p:h=U  
{ O4.`N?Xq  
this("",0); iu+r=s p  
} |s$w i>7l  
rCp'O\@S  
V>Vu)7  
public FileAccessI(String sName,long nPos) throws IOException +9!=pRq  
{ j|Hyv{sM  
oSavedFile = new RandomAccessFile(sName,"rw"); $WS?/H0C  
this.nPos = nPos; #Li6RSeW  
oSavedFile.seek(nPos); O-jpS?@  
} 'BO MFp7c  
_(%;O:i  
{GP#/5$=  
public synchronized int write(byte[] b,int nStart,int nLen) #<*=)[  
{ =d M'n}@U  
int n = -1; a 0+W-#G  
try{ vnS;T+NZSC  
oSavedFile.write(b,nStart,nLen); EYXHxo  
n = nLen; ; xx u,  
} r&_bk Y%  
catch(IOException e) L }L"BY3$  
{ aF]cEe  
e.printStackTrace (); ews{0  
} cy @",z  
[wv;CUmgc  
p38RgEf  
return n; fIwG9cR  
} '74*-yd  
>o,l/# z  
>,}SP;  
} fuao*L]  
e` {F7rd:  
*1c1XN<7  
/* 6h9Hf$'  
**SiteInfoBean.java # ; 3v4P  
*/ *aaK_=w  
package NetFox; ]b'" l  
cl1>S3  
eB2a1<S&@  
public class SiteInfoBean { ~;/}D0k$x  
$3)Z>p   
dk>qTY+j5  
private String sSiteURL; //Site's URL - xKa-3  
private String sFilePath; //Saved File's Path ,LftQ1*;  
private String sFileName; //Saved File's Name 6O\a\z  
private int nSplitter; //Count of Splited Downloading File X-k$6}D  
n&\DJzW\#  
|kK_B :K  
public SiteInfoBean() Bm4fdf#A]  
{//nSplitter的缺省值为5 $*q^7ME  
//default value of nSplitter is 5 HyGu3  
this("","","",5); 8'|_O  
} '9XSz?  
o_R_  
\9N )71n(  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) m4x8W2q  
{ mZ0'-ax   
sSiteURL= sURL; /ht-]Js$G  
sFilePath = sPath; NnTAKd8  
sFileName = sName; D&*'|}RZ  
this.nSplitter = nSpiltter; B x-"<^<  
JrNqS[c/  
":W$$w<  
} @5tGI U;1  
v\3$$T)  
/ei(Q'pc[  
public String getSSiteURL() u`?v-   
{ S pIdw0  
return sSiteURL; ;GV~MH-F  
} K'U8ft*_  
e]zd6{g[m  
Z# o;H$  
public void setSSiteURL(String value) ^t}8E2mq  
{ bvF-F$n%F  
sSiteURL = value; t .-%@,s  
} "|nh=!L  
Ng|c13A=  
12LGWhDp  
public String getSFilePath() EZJ[+ -Q;  
{ ;i-<dAV8B  
return sFilePath; *_@t$W  
} "Ta"5XW  
'n/L1Fn  
[ XBVES8  
public void setSFilePath(String value) U#g ,XJ  
{ w^E$R  
sFilePath = value; s6(bTO.  
} 'mYUAVmSC#  
k] iyx  
):Pz sz7  
public String getSFileName() RN"Ur'+  
{ -jk-ve  
return sFileName; OJT%?P%@{  
} ;5&=I|xqe  
|32uC3?o  
\\Te\l|L  
public void setSFileName(String value) `h='FJ/!  
{ r^T+ I3  
sFileName = value; W0k7(v)  
} a/TeBx#yG  
NudY9 ~   
Lk2;\D>  
public int getNSplitter() Ctx{rf_~  
{ ]/[$3rPwZ  
return nSplitter; `=P=i>,  
} c1ptN  
bBY7^k  
,b9!\OWDF  
public void setNSplitter(int nCount) :0'vzM  
{ khVfc  
nSplitter = nCount; % 8P8h%%Z  
} ZmAo9>'Kg  
} Mn TqWC90  
:vJ1Fo!  
o?/fObV@(  
/* bkS-[rW  
**Utility.java tqXCj}mR  
*/ V6kJoSyde  
package NetFox; dmPAPCm%y  
W%@0Ym `7  
,'%*z  
public class Utility { FZ5 Ad&".@  
,m[#<}xXA  
[7Liken  
public Utility() &0RKNpw g  
{ ;4k/h/o1#  
-\~HAnh  
@Px_\w  
} "{x+ \Z\  
!|~yf3  
//线程睡眠 ,SH^L|I  
public static void sleep(int nSecond) -=GmI1:=$4  
{  L0>7v  
try{ K'oy6$B  
Thread.sleep(nSecond); Oid;s!-S6  
} t/J|<Ooj?  
catch(Exception e) C&f{LpB`  
{ q"VC#9 7`  
e.printStackTrace (); 2#X>^LH  
} IHwoG(A~<  
} +6s6QeNS8  
JZ)w  
//日志 8iC9xSH[%  
public static void log(String sMsg) #D^( dz*  
{ V-ONC  
System.err.println(sMsg); IgEVz^W?h  
} 9#1Jie$  
o3Z<tI8-V  
Lklb  
public static void log(int sMsg) WDF6.i ?  
{ J<MuWgx&  
System.err.println(sMsg); Nt~G  {m  
} rw%OA4>  
} P\&n0C~  
=\g K<Xh  
m%U$37A 1  
/* x,Z:12H0  
**TestMethod.java vz^=o'  
*/ $KPf[JvQ  
package NetFox; TNlS2b1  
!RwMUnp  
Q+p9^_r  
public class TestMethod { "@L|Z6U(  
R<Ct{f!  
ggUw4w/e  
public TestMethod() V3$zlzSm,  
{ ///xx/weblogic60b2_win.exe ~vKDB$2  
try{ P(B&*1X  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pt%Y1<9Eh?  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); wp<f{^ et  
SiteFileFetch fileFetch = new SiteFileFetch(bean); USV;j%U4*  
fileFetch.start(); RY]jY | E  
} YbJB.;qK  
catch(Exception e){e.printStackTrace ();} ;RS^^vDm  
Vo9Fl Yj  
NW~`oc)NS  
} 9^@#Ua  
6OZ n7:)Y  
p*|Ct  
public static void main(String[] args) K}QZdN']  
{ /U= ?D(>x  
new TestMethod(); =~'y'K]  
} &Y-jK<  
} QxiAC>%K  
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