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http断点续传简单实现(java)

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/* ljlQ9wb[s  
**SiteFileFetch.java #Ji&.T^U/  
*/ o D*h@yL  
package NetFox; km}%7|R?  
import java.io.*; J5mMx)t@  
import java.net.*; Nf}G "!  
]gQgNn?  
yg5Ik{  
public class SiteFileFetch extends Thread { Xi6XV3G  
|bO}|X  
S$=])^dur  
SiteInfoBean siteInfoBean = null; //文件信息Bean b9%hzD,MR  
long[] nStartPos; //开始位置 A>bo Xcr  
long[] nEndPos; //结束位置 2Af1-z^^K  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 -$QzbRF5R  
long nFileLength; //文件长度 ?r'rvu'/  
boolean bFirst = true; //是否第一次取文件 R}#?A%,*  
boolean bStop = false; //停止标志 Wepa;  
File tmpFile; //文件下载的临时信息 E/Q[J.$o  
DataOutputStream output; //输出到文件的输出流 z$QYl*F1  
-Z-|49I/mN  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) a^@6hC>sr  
public SiteFileFetch(SiteInfoBean bean) throws IOException MkRRBvk  
{ u1~H1 ]Ii  
siteInfoBean = bean; ss-{l+Z5  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); >TeTa l  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); V[(zRGa{  
if(tmpFile.exists ()) (caxl^=  
{ 6*lTur9ni  
bFirst = false; ?N~rms e  
read_nPos(); xeIt7b?#  
} E"b+Q  
else 0%<Fc9#  
{ ^}a..@|%W  
nStartPos = new long[bean.getNSplitter()]; jri=UGf  
nEndPos = new long[bean.getNSplitter()]; gH,^XZe  
} P@`@?kMU  
\uc]+nV!o  
Ev,>_1#Xm  
JpcG5gX^B  
} p[!&D}&6h  
VA&_dU]*  
d!D#:l3;  
public void run() >KNiMW^V  
{ ]t=m  
//获得文件长度 K pDKIi  
//分割文件 MD1n+FgTu  
//实例FileSplitterFetch QaH32(iH  
//启动FileSplitterFetch线程 5*/~) wN\U  
//等待子线程返回 >OgA3)X  
try{ Ovxs+mQ  
if(bFirst) [1F.   
{ pi*cO  
nFileLength = getFileSize(); pV9$Vg?-H  
if(nFileLength == -1) `+CRUdr  
{ (oBvpFP33  
System.err.println("File Length is not known!"); bg'Qq|<U  
} o+*YX!]#L  
else if(nFileLength == -2) p`fUpARA!  
{ F/tGk9v  
System.err.println("File is not access!"); AU -,  
} A_tdtN<  
else >=G;rs  
{ tda#9i[pkH  
for(int i=0;i<nStartPos.length;i++) eGkB#.+J!  
{ Sb+^~M  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); &xo_93  
} W4%I%&j  
for(int i=0;i<nEndPos.length-1;i++) 5/F1|N4  
{ @SjISZw_  
nEndPos = nStartPos[i+1]; zR_ "  
} s!:'3[7+  
nEndPos[nEndPos.length-1] = nFileLength; ><V<}&:y$(  
} $M5iU@A  
} M+j V`J!  
j^;f {0f  
oCg|* c|+  
//启动子线程 Y``50{7  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; xAbx.\  
for(int i=0;i<nStartPos.length;i++) 1YV ;pEw3w  
{ e{EKM4  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w j !YYBH  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), A=JPmsj.  
nStartPos,nEndPos,i); lD)ZMaaS3  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Hb55RilC  
fileSplitterFetch.start(); D_]4]&QYT  
} 4 3V {q  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), & Xm !i(i  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <'N"GLJ  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", mE=%+:o.  
nEndPos = " + nFileLength); mhVdsa  
// fileSplitterFetch[nPos.length-1].start(); [1nfSW  
o-a\T  
d0``:  
//等待子线程结束 8JYU1E w  
//int count = 0; :d}I`)&  
//是否结束while循环 .;}vp*  
boolean breakWhile = false;  UCV1{  
!k@ (}CN_*  
GVR/p  
while(!bStop) L|ZxB7xk  
{ ]dIcW9a  
write_nPos(); Nk?eVJ)  
Utility.sleep(500); opsjei@  
breakWhile = true; xl2;DFiYt  
%])U(  
'tvX.aX2  
for(int i=0;i<nStartPos.length;i++) cQ}3? v  
{ 1i3;P/  
if(!fileSplitterFetch.bDownOver) v+d} _rCT  
{ 7" Qj(N  
breakWhile = false; ZDny=&>#  
break; K93L-K^J  
} %4'<0  
} qJ(XW N H  
if(breakWhile) yUnNf 2i  
break; H j [!F%  
K Q^CiX  
F3nYMf  
//count++; =sZ58xA  
//if(count>4) )hG4,0hv&  
// siteStop(); .ni<'  
} !aQb Kp  
AS4mJ UU9  
Lmsc ~~  
System.err.println("文件下载结束!"); 8]h~jNku  
} 5tx!LGOK  
catch(Exception e){e.printStackTrace ();} @n,V2`"  
} ~'1gX`o:  
&A}hx\_T  
B']-4X{SGa  
//获得文件长度 .fFXH  
public long getFileSize() 4j|IG/m  
{ y'L7o V?L9  
int nFileLength = -1; mHe[ NkY6  
try{ ba-4V8w  
URL url = new URL(siteInfoBean.getSSiteURL()); !E7JDk''@  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {ooztC   
httpConnection.setRequestProperty("User-Agent","NetFox"); FD'yT8]"  
cl04fqX  
#ZkT![ `  
int responseCode=httpConnection.getResponseCode(); !,lk>j.V  
if(responseCode>=400) 9]C%2!Ur,  
{ "hi d3"G  
processErrorCode(responseCode); AjVX  
return -2; //-2 represent access is error e dTFk$0  
} iX%9$Bft<  
7f] qCZ<0V  
+[vI ocu  
String sHeader; uwl_TDc>%  
JAx0(MZO  
x52#md-Z  
for(int i=1;;i++) fHK.q({Qc  
{ &R5zt]4d&  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); A=W:}szt]  
//Utility.log(in.readLine()); .Ht;xq  
sHeader=httpConnection.getHeaderFieldKey(i); }#r awVe=  
if(sHeader!=null) {x{~%)-  
{ :%_\!FvS  
if(sHeader.equals("Content-Length")) Gsn$r(m{K  
{ p<[MU4  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); t)|~8xpP  
break; <@Z`<T6  
} R1$s1@3I|  
} E$.fAIt  
else UpaF>,kM  
break; 71n3d~!O>  
} qCkC 2Fy(  
} v]Fw~Y7l!  
catch(IOException e){e.printStackTrace ();} "%}24t%  
catch(Exception e){e.printStackTrace ();} GXaPfC0-y  
@r&*Qsf|   
 8 X Qo  
Utility.log(nFileLength); N TcojA{V$  
p$=Z0p4%LL  
KFg q3snH  
return nFileLength; YdDP;, DA  
}  VBUrtx:  
GQ(*k)'a  
OxQ5P;O  
//保存下载信息(文件指针位置) &V| kv"Wwj  
private void write_nPos() w_h{6Kc<  
{ cgnMoBIc  
try{ jB<B_"  
output = new DataOutputStream(new FileOutputStream(tmpFile)); oN2#Jh%dH  
output.writeInt(nStartPos.length); Q5c3C &$6  
for(int i=0;i<nStartPos.length;i++) 0qINa:Ori  
{ >?O?U=:<  
// output.writeLong(nPos); IClw3^\l  
output.writeLong(fileSplitterFetch.nStartPos); !YPwql(  
output.writeLong(fileSplitterFetch.nEndPos); 7Kf  
} :w q][0)  
output.close(); oam$9 q  
} zLgc j(;  
catch(IOException e){e.printStackTrace ();}  !2kM  
catch(Exception e){e.printStackTrace ();} fMIRr5  
} k%3)J"|/  
+ -uQ] ^n  
<6Y|vEo!N  
//读取保存的下载信息(文件指针位置) _\=x A6!  
private void read_nPos() B(WmJ6e  
{ ;>uB$8<_7  
try{ B}S+/V` Y5  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3[j,d]\|  
int nCount = input.readInt(); o}DR p4;Ka  
nStartPos = new long[nCount]; _dELVs7OL  
nEndPos = new long[nCount]; Iprt ZqiL  
for(int i=0;i<nStartPos.length;i++) T+^Sa J  
{  v%$l(  
nStartPos = input.readLong(); ht*N[Pi4;  
nEndPos = input.readLong(); _&~l,%)&  
} ,hH c -%-  
input.close(); i=L 86Ks  
} {yv_Ni*6!  
catch(IOException e){e.printStackTrace ();} I{ Ip  
catch(Exception e){e.printStackTrace ();} : tBe/(e4#  
} )RN3Oz@H  
=;+gge!?bB  
O|S,="h"}  
private void processErrorCode(int nErrorCode) L(bDk'zi  
{ O:sqm n  
System.err.println("Error Code : " + nErrorCode); ] )iP?2{  
} ~5&B#Sm[G  
#K0/ >W  
)!kt9lK  
//停止文件下载 tA^+RO4  
public void siteStop() ZJF"Yo  
{ %%F, G  
bStop = true; Z^]jy>dj  
for(int i=0;i<nStartPos.length;i++) 'z^'+}iyv  
fileSplitterFetch.splitterStop(); Ypl;jkHP  
#8sy QWlG  
=@ acg0  
} >|, <9z`D  
} ~;jgl_5?b  
//负责部分文件的抓取 7m  ou  
**FileSplitterFetch.java vp2w^/])u  
*/ -.r"|\1X  
package NetFox; TFG? EO  
D_?Tj  
ZR -RzT1  
import java.io.*; KTt+}-vP^  
import java.net.*; !zt>& t  
i6P}MtC1  
g4=C]\1  
public class FileSplitterFetch extends Thread { YO-B|f  
e,{k!BXU#'  
yKuZJXGVo  
String sURL; //File URL '$Z@oCY#  
long nStartPos; //File Snippet Start Position A +=#  
long nEndPos; //File Snippet End Position VH4wsEH]  
int nThreadID; //Thread's ID z{&Av  
boolean bDownOver = false; //Downing is over ZJW8S  
boolean bStop = false; //Stop identical uB^"A ;0v  
FileAccessI fileAccessI = null; //File Access interface %19~9Tw  
 pdm(7^  
z:Tj0< A'  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException n-2!<`UFX  
{ tH&eKM4G  
this.sURL = sURL; tvf5b8(Y-  
this.nStartPos = nStart; ?FNgJx*\S  
this.nEndPos = nEnd; y{&%]Fq <5  
nThreadID = id; k-a1^K3  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 I{[}1W3]W  
}  5k@T{  
g)\Tex<  
Op8Gj  `  
public void run() fPHV]8Ft|  
{ *^Zt)U1$|  
while(nStartPos < nEndPos && !bStop) }cI-]|)|2  
{ ?mM:oQH+>  
X31%T"  
0C.5Qx   
try{ sxA]o|  
URL url = new URL(sURL); \pkK >R  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cuH5f}oc  
httpConnection.setRequestProperty("User-Agent","NetFox"); ppRA%mhZ  
String sProperty = "bytes="+nStartPos+"-"; 5Pq6X  
httpConnection.setRequestProperty("RANGE",sProperty); 9od c :  
Utility.log(sProperty); N<@K(? '  
#'O9Hn({  
 H{yBD xw  
InputStream input = httpConnection.getInputStream(); "!(@MfjT  
//logResponseHead(httpConnection); p>kny?AJ  
*J]p/<> {  
AA)pV-  
byte[] b = new byte[1024]; "9d Z z/{  
int nRead; eaNfCXHDN  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) wEl7mg !  
{ -W.-m2:1  
nStartPos += fileAccessI.write(b,0,nRead); 3 ^x&G?)  
//if(nThreadID == 1) I$S*elveG  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jl}!UG  
} Xs|d#WbX  
K|\0jd)N  
n^$Q^[:Z  
Utility.log("Thread " + nThreadID + " is over!"); 0[fBP\H"Wr  
bDownOver = true; @`+\v mfD  
//nPos = fileAccessI.write (b,0,nRead); ^7ID |uMr  
} shL_{}  
catch(Exception e){e.printStackTrace ();} [qV/&t|O*h  
} c%O97J.5b  
} aCH;l~+U  
c$)>$&([  
!( +M  
//打印回应的头信息 ]mi\Y"RO  
public void logResponseHead(HttpURLConnection con) cAGM|%  
{ bf=\ED^  
for(int i=1;;i++) hrD2 -S  
{ X jxa 2D  
String header=con.getHeaderFieldKey(i); !]}C!dXd  
if(header!=null) f3n^Sw&Q(Q  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); t5_76'@cX  
Utility.log(header+" : "+con.getHeaderField(header)); Z ztp %2c  
else y${`W94  
break; -hfkF+=U'  
} suIYfjh  
} o<p4r}*AVJ  
%-fS:~$  
A@?-"=h}  
public void splitterStop() p<h(  
{ bC"h7$3  
bStop = true; Ac{TqiIv  
} ^b~ZOg[p  
_t;^\"\  
-IVWkA)7  
} OGLA1}k4  
G5OGyQp  
(VmFYNt&  
/* mJd8?d  
**FileAccess.java "[k>pzl6  
*//文件访问(定位,写) yMM2us#*+q  
package NetFox; G;#xcld  
import java.io.*; DF-PBVfpu  
Vv5T(~   
OAFxf,b  
public class FileAccessI implements Serializable{ 6< -Cpc  
u\iKdL  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 oxeIh9 E  
RandomAccessFile oSavedFile; gBWr)R  
long nPos; =Ez@kTvOs  
W5Jy"]^I  
3TeRZ=2:*x  
public FileAccessI() throws IOException 9bRUN<  
{ E}F-*go  
this("",0); 6{udNv X  
} 5+Tx01 )  
8[t*VIXI  
hT_Q_1,  
public FileAccessI(String sName,long nPos) throws IOException k^ fW /  
{ *' es(]W  
oSavedFile = new RandomAccessFile(sName,"rw"); q9VBK(,X  
this.nPos = nPos; :/6aBM?  
oSavedFile.seek(nPos); v8'XchJ  
} .}eM"Kv  
.waj.9&[l  
R}3th/qf  
public synchronized int write(byte[] b,int nStart,int nLen) K0o${%'@7  
{ MK! @ND  
int n = -1; C8qSoO4Z  
try{ .X(qs1  
oSavedFile.write(b,nStart,nLen); p/u  
n = nLen; ek/zQM@%  
} lb*;Z7fx<'  
catch(IOException e) ">h$(WCK  
{ thX4-'i  
e.printStackTrace (); 90Sras>F  
} b{ A/M#=  
-$#2?/uqC  
Voq/0,d  
return n; J(~1mIJjC  
} z[Qe86L  
_ MB/p  
(E,[Ad,$  
} Unq~lt%2  
nFI<Te^)  
l O*  
/* (M u;U!M"P  
**SiteInfoBean.java vg@5`U`^h  
*/ 9C Ki$L  
package NetFox; ,JbP~2M~%  
m :~y:.  
.X)Wb{7  
public class SiteInfoBean { Ay^P #\VZ  
-#G>`T~  
,Csjb1  
private String sSiteURL; //Site's URL P*%P"g  
private String sFilePath; //Saved File's Path <tsexsw  
private String sFileName; //Saved File's Name i| ,}y`C#  
private int nSplitter; //Count of Splited Downloading File H"Hl~~U  
Tj!\SbnA[  
3fX _XH1Q  
public SiteInfoBean() N7}3?wS  
{//nSplitter的缺省值为5 7B5b +  
//default value of nSplitter is 5 PBEi"`i  
this("","","",5); U1fqs{>  
} CK|AXz+EN  
#cW :04  
xX{Zh;M&[  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]mNsG0r6  
{ Oi$1maxT  
sSiteURL= sURL; [ybK  
sFilePath = sPath; R^$EnrY(<  
sFileName = sName; =b1 y*?  
this.nSplitter = nSpiltter; X&rsWk  
<4@8T7  
)Spa F)N8  
} D^p)`*  
*> Be w  
PQYJn x}  
public String getSSiteURL() WD[jEWMV7D  
{ luac  
return sSiteURL; |f1^&97=+  
} 2>9..c  
FjiIB1 T  
s`[V{1m,  
public void setSSiteURL(String value) dWi.V?K4z  
{ L*4= b (3  
sSiteURL = value; X_bB6A6  
} 8WpNlB+:{  
{x..> 4  
q&NXF (  
public String getSFilePath() {-]K!tWda  
{ ;p <BiC$b  
return sFilePath; iyUnxqP  
} ,+C?UW  
w}(pc }^U  
=,qY\@fq  
public void setSFilePath(String value) <pKOFN%m  
{ -'WR9M?fq  
sFilePath = value; >XRf= :3  
} n+<  
,VUOsNN4\  
KIWHn_ :  
public String getSFileName() xdaq` ^Bbt  
{ 2VX9FDrnk  
return sFileName; 1~2+w]-kU  
} #}~?8/h!  
R*k;4*1u  
z-"P raP  
public void setSFileName(String value) Q.V@Sawe5  
{ @<4U &  
sFileName = value; `jhbKgR[  
} o"P)(;  
I*a .!/$)  
Hl{ul'o  
public int getNSplitter() ft0d5n!ui4  
{ ,Tx38  
return nSplitter; ZdPqU \G^q  
} oz|+{b}%  
Z R~2Y?Wt9  
"Z&_*F.[O  
public void setNSplitter(int nCount) _pvt,pW  
{ XMxm2-%olP  
nSplitter = nCount; C+t|fSJ  
} Z3u6m0!  
} <RH%FhT  
Su +<mW  
b%C7 kL-  
/* U!BZs Vx  
**Utility.java ?LvU7  
*/ [ {vX*q 3B  
package NetFox; =W"T=p*j  
!kh:zTP  
<9$Pl%:  
public class Utility { + I*a=qjq  
u'T>Y1I  
3{ea~G)[9  
public Utility() W>b\O">  
{  3(*vZ  
i_`Po%   
Zba<|C  
} LCHw.  
Pe11a zJ  
//线程睡眠 ]]_c3LJ2`  
public static void sleep(int nSecond) dww4o~hO  
{ FS!vnl8`  
try{ or7l} X  
Thread.sleep(nSecond); *8u<?~9F  
} a%an={  
catch(Exception e) 5~#oQ&  
{ w-@6qMJ  
e.printStackTrace (); ye}86{l  
} J~ *>pp#U  
} G#E8xA"{/  
IkGM~3e  
//日志 0/%RrE  
public static void log(String sMsg) U` )d `4"  
{ tpgD{BY^wJ  
System.err.println(sMsg); b`;&o^7gMO  
} g]?>6 %#rA  
,d^HAg^j  
<<@F{B7h  
public static void log(int sMsg) Ca/N'|}^  
{ +*e Vi3  
System.err.println(sMsg); <0Gk:NB,  
} -xyY6bxL  
} ybIqn0&[  
iUqD>OV  
Fd%JF#Hk  
/* T=g2gmo9  
**TestMethod.java PbV1FB_  
*/ 01]W@ \(  
package NetFox; F"23v G>3  
N~?#Qh|ZnU  
jPc,+?  
public class TestMethod { Y|KT3  
Cw5 B p9  
nLrCy5R:  
public TestMethod() @j(2tJ,w  
{ ///xx/weblogic60b2_win.exe 6"r _Y7%  
try{ :/>Zky8,k  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); {aU|BdATI  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); (H]NL   
SiteFileFetch fileFetch = new SiteFileFetch(bean); A9GSeW<  
fileFetch.start(); 9R[P pE''  
} yRp&pUtb  
catch(Exception e){e.printStackTrace ();} _0iV6Bj  
<e@4;Z(h04  
lpbcpB  
} 4#B 56f8  
wkJ@#jD*[  
g/w <T+v  
public static void main(String[] args) iBKH\em/  
{ od&wfwk(  
new TestMethod(); dI%Nwl%  
} _.m|Ml,`{  
} D'UIxc8  
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