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http断点续传简单实现(java)

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/* z*e`2n#\  
**SiteFileFetch.java r<OqI*7  
*/ Nz;f| 2h  
package NetFox; L2> )HG  
import java.io.*; ]=G  dAW  
import java.net.*; r,Tq";N'  
MHQM'  
ZfVw33z  
public class SiteFileFetch extends Thread { &6&$vF65c  
%(A@=0r#  
b NR@d'U  
SiteInfoBean siteInfoBean = null; //文件信息Bean ~9Cw5rwH<;  
long[] nStartPos; //开始位置 99*QfC  
long[] nEndPos; //结束位置 >=K~*$&>  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 (Qd@Q,@(s  
long nFileLength; //文件长度 zn#lFPj12  
boolean bFirst = true; //是否第一次取文件 -'rb+<v  
boolean bStop = false; //停止标志 hh8U/dVk*  
File tmpFile; //文件下载的临时信息  Q5 =  
DataOutputStream output; //输出到文件的输出流 F@<^  
"sJ@_lp  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) }e-D&U  
public SiteFileFetch(SiteInfoBean bean) throws IOException ffG1QvC|M  
{ &UIS17cT  
siteInfoBean = bean; F5 7Kr5X  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 3(3-#MD0  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); jhB+ ]  
if(tmpFile.exists ()) |\T!,~  
{ S.|%dz  
bFirst = false; }WnoI2  
read_nPos(); chXTFLC~  
} WQBpU?O  
else aC#{@t  
{ o+g\\5s  
nStartPos = new long[bean.getNSplitter()]; $g  '4'  
nEndPos = new long[bean.getNSplitter()]; [/Xc},HbMe  
} ZN}U^9m=  
seiE2F[  
cF}9ldc  
HY,VJxR[  
} sWFw[ Y>  
@<z#a9  
xV.UM8  
public void run() ?7dV:]%~2  
{ xcX^L84\  
//获得文件长度 4%*`' o$_  
//分割文件 CGs5`a  
//实例FileSplitterFetch 4?Qc&e{5  
//启动FileSplitterFetch线程 b5?k)s2  
//等待子线程返回 PJ2m4ulY  
try{ 7-MyiCt  
if(bFirst) !yu-MpeG  
{ 1i}p?sU  
nFileLength = getFileSize(); pykRi#[UrX  
if(nFileLength == -1) V"5LNtf  
{ `o6T)49  
System.err.println("File Length is not known!"); q(Zu;ecBN  
} xbs X-F  
else if(nFileLength == -2) 7l3Dx w/N  
{ D)bR-a_^  
System.err.println("File is not access!"); 3yu,qb'"&  
} `3L?x8g  
else Qk8YR5 K   
{ Z4{~  
for(int i=0;i<nStartPos.length;i++) :tp{(MF  
{ E[M.q;rM  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); G$1gk^G's  
} 5](,N^u{):  
for(int i=0;i<nEndPos.length-1;i++) #Kt5+"+7  
{ =po5Q6@i  
nEndPos = nStartPos[i+1]; +?+iVLr!l}  
} pXf5/u8&  
nEndPos[nEndPos.length-1] = nFileLength; S<>u  
} @pV&{Vp  
} Q#}c5TjVr  
$}.#0c8I  
' eH Fa  
//启动子线程 w"OeS;#e:  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *wV`7\@  
for(int i=0;i<nStartPos.length;i++) %$=}ePD  
{ m-'+)lB  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0 2q*z>:^  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), fX}dQN~z  
nStartPos,nEndPos,i); !==C@cH<N  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zqm/<]A*l  
fileSplitterFetch.start(); ;c|G  
} 4n/CS AT1  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <v$yXA  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :2-!bLo}&  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", M][Zu[\*  
nEndPos = " + nFileLength); /igbn  
// fileSplitterFetch[nPos.length-1].start(); A#CGD0T  
xcC^9BAj  
7jYW3  
//等待子线程结束 HfA@tZ5q|U  
//int count = 0; U_Am Riy  
//是否结束while循环 :{x    
boolean breakWhile = false; MXynv";<H  
i~.9 B7hdE  
hA387?  
while(!bStop) Jl{g"N{2u'  
{ qWw{c&{Q],  
write_nPos(); O],]\M{GL  
Utility.sleep(500); 7-[^0qS  
breakWhile = true; #& &  
;"+]bne~  
rB.LG'GG]  
for(int i=0;i<nStartPos.length;i++) W(jP??up  
{ eG%Q 3h  
if(!fileSplitterFetch.bDownOver) e*pYlm  
{ RhI>Ak;-  
breakWhile = false; dwmZ_m.  
break; |"k+j_/+  
} o '!WW  
} 5+Hw @CY3  
if(breakWhile) Tw!_=zy(Gw  
break; )X5en=[)O  
Schvwlm~i  
7=pJ)4;ZA  
//count++; +t<'{KZ7;  
//if(count>4) Hb@PQcj  
// siteStop(); ,Cj` 0v#  
} R;F z"J  
)r6d3-p1  
);*#s~R  
System.err.println("文件下载结束!"); P: )YKro]  
} 3L-}B#tI  
catch(Exception e){e.printStackTrace ();} 0 A6% !h  
} 7A4_b8  
Nx<%'-9)|  
z#t;n  
//获得文件长度 5hE mXZ%  
public long getFileSize() fz`\-"f]  
{ U-lN-/=l6  
int nFileLength = -1; h|XLL|:  
try{ 5)<}a&;{  
URL url = new URL(siteInfoBean.getSSiteURL()); :DR}lOi`  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p|VgtQ/ )%  
httpConnection.setRequestProperty("User-Agent","NetFox"); 4'U #<8  
Wf5ohXm>  
m7NrS?7  
int responseCode=httpConnection.getResponseCode(); p^?]xD(  
if(responseCode>=400) jt4c*0z  
{ <h mRr  
processErrorCode(responseCode); KcF#c_f   
return -2; //-2 represent access is error =Vi>?fWpn=  
} AJR`ohh  
cj9<!"6  
FdM xw*}  
String sHeader; )L%[(iI,x  
1bpjj'2%x  
Ah1fcXED  
for(int i=1;;i++) i")ucrf  
{ 3NxwQ,~  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +G lb  
//Utility.log(in.readLine()); t.= 1<Ed  
sHeader=httpConnection.getHeaderFieldKey(i); 88M$mjx  
if(sHeader!=null) 6@cT;=W;xj  
{ Zh 3hCxXa  
if(sHeader.equals("Content-Length")) }pL#C  
{ a^.5cJ$]  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); f)%8*B  
break; _Sn7z?  
} br_D Orq|  
} G5'HrV  
else yfCdK-9+B  
break; A"R5Fd%6pc  
} Q:sw*7"F  
} Qr$Ay3#k  
catch(IOException e){e.printStackTrace ();} \KT}T  
catch(Exception e){e.printStackTrace ();} 9ld'SB:#  
*/E5<DO  
=U_O;NC  
Utility.log(nFileLength); }='1<~0  
<ZgbmRY8  
M3/_E7Qoj  
return nFileLength; gDBdaxR<  
} 9 M!J7 W  
,pMH`  
n0< I  
//保存下载信息(文件指针位置) ]Z#=w  
private void write_nPos() 9|9Hk1  
{ k\`~v$R3  
try{ nK;c@!~pS  
output = new DataOutputStream(new FileOutputStream(tmpFile)); sqP (1|9  
output.writeInt(nStartPos.length); \oc*  
for(int i=0;i<nStartPos.length;i++) #JIh-h@  
{ "0#d F:qt  
// output.writeLong(nPos); 6 s1lf!  
output.writeLong(fileSplitterFetch.nStartPos); + 4*jO5EZ  
output.writeLong(fileSplitterFetch.nEndPos); 'Z=8no`<  
} AQa;D2B$  
output.close(); pQf5s7  
} "~^ #{q  
catch(IOException e){e.printStackTrace ();} A6# 5 z  
catch(Exception e){e.printStackTrace ();} gS$?#!f  
} fkmN?CU{1%  
v"N%w1`.e  
Me XGE  
//读取保存的下载信息(文件指针位置) F ;;\I  
private void read_nPos() jizp\%W+  
{ `X ;2lgL  
try{ POtwT">z  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); xgV(0H}Mf  
int nCount = input.readInt(); J5 2- qR/  
nStartPos = new long[nCount]; hxQx$  
nEndPos = new long[nCount]; 2J5RZg9jL  
for(int i=0;i<nStartPos.length;i++) Wz]ny3K[.  
{ {,`)  
nStartPos = input.readLong(); ^a+H`RD  
nEndPos = input.readLong(); zv}3Sl@  
} aS,M=uqqK  
input.close(); qkk!1W  
} _bm8m4Lk  
catch(IOException e){e.printStackTrace ();} EmO{lCENk  
catch(Exception e){e.printStackTrace ();} mM6X0aM  
} 'ZboLoS*-  
B(TE?[ #  
s}5,<|DL  
private void processErrorCode(int nErrorCode) CV )v6f  
{ VA^yv1We  
System.err.println("Error Code : " + nErrorCode); [9U: :  
} 0V_dg |.  
6mAaFDI,R  
+P5\N,,7R  
//停止文件下载 %SHgXd#X  
public void siteStop() v62M8r,Y  
{ dNg5#?mzT5  
bStop = true; ap y#8]  
for(int i=0;i<nStartPos.length;i++) XD=p:Ezh  
fileSplitterFetch.splitterStop(); Ns}BE H  
WY)*3?  
] eO25,6  
} Dq:>]4%  
} y/(60H,{{  
//负责部分文件的抓取 ;VI/iwg  
**FileSplitterFetch.java mufJ@YS#  
*/ `: R7j f  
package NetFox; 7I0[Ii  
Z>t,B%v  
)E hR qX9  
import java.io.*; P^Tk4_,0  
import java.net.*; j{?ogFfi  
vl,Ff9  
3{*nG'@Mal  
public class FileSplitterFetch extends Thread { Q eZg l!  
S_ELV#X  
JsZLBq*lP  
String sURL; //File URL 9\J.AAk~/  
long nStartPos; //File Snippet Start Position <<5x"W(,  
long nEndPos; //File Snippet End Position LI`H,2Km  
int nThreadID; //Thread's ID [')C]YQb=  
boolean bDownOver = false; //Downing is over ,N`cH\  
boolean bStop = false; //Stop identical e*?@6E  
FileAccessI fileAccessI = null; //File Access interface )GC9%mF;  
_ a`J>~$  
_d`)N  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &u}]3E'-k  
{ :*6#(MX  
this.sURL = sURL; ,u&K(Z%  
this.nStartPos = nStart; |Y")$pjz  
this.nEndPos = nEnd; W8><  
nThreadID = id; 6PyODW;R/5  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 P1>?crw  
} &4R -5i2a  
]QJWqY  
![l`@NH[U  
public void run() 2C59fXfd  
{ vkgAI<  
while(nStartPos < nEndPos && !bStop) WPpS?  
{ dtDT^~  
zHu w[  
\zMx~-2oN  
try{ pX LXkF?  
URL url = new URL(sURL); |[B JZ  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8uD%  
httpConnection.setRequestProperty("User-Agent","NetFox"); |iLf;8_:  
String sProperty = "bytes="+nStartPos+"-"; Rxfhk,I  
httpConnection.setRequestProperty("RANGE",sProperty); .FWi$B';  
Utility.log(sProperty); 5%K(tRc|  
ucwUeRw,  
JMVh\($,x  
InputStream input = httpConnection.getInputStream(); Sz'H{?"  
//logResponseHead(httpConnection); )ld`2) 4  
1[k.apn  
*MM8\p_PuT  
byte[] b = new byte[1024]; OS]FGD3a  
int nRead; N6thbH@  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) z1vSt[s  
{ nSR<(-j!  
nStartPos += fileAccessI.write(b,0,nRead); 59X'-fg,  
//if(nThreadID == 1) ! a!^'2  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .;,` bH0  
} %SKJ#b  
9tBE=L=  
CjT]!D)s  
Utility.log("Thread " + nThreadID + " is over!"); 3^-yw`  
bDownOver = true; RJa1p YK  
//nPos = fileAccessI.write (b,0,nRead); I\WBPI  
} WN6%%*w  
catch(Exception e){e.printStackTrace ();} |:b!e  
} >uy(N  
} K^f&+`v6_  
]rM HO  
2}xvM"k=k  
//打印回应的头信息 $dkkgsw 7  
public void logResponseHead(HttpURLConnection con) *h)|K s  
{ v~`'!N8  
for(int i=1;;i++) ,%4~ulKMn  
{ =Yt)b/0b9  
String header=con.getHeaderFieldKey(i); O&@pi-=o  
if(header!=null) "^&Te%x_b  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;oGpB#[zO  
Utility.log(header+" : "+con.getHeaderField(header)); ''3b[<  
else 9~ r YLR(v  
break; }Jm~b9j  
} gBd@4{y6C.  
} \@F~4,VT  
7I;A5f  
ka?EXF:  
public void splitterStop() E;-*LT&{  
{ k@Mt8Ln  
bStop = true; y@2$sK3K  
} [iGL~RiXtn  
07#e{   
mr<camL5  
} s MNhD/bb  
+LB2V3UZ  
WNcJ710k27  
/* e763 yd  
**FileAccess.java 45U!\mG  
*//文件访问(定位,写) UtYwG#/w  
package NetFox; $c1xh.  
import java.io.*; qi=v}bp&  
)Nnrsa  
(K`@OwD  
public class FileAccessI implements Serializable{ |$G|M=*LN  
qj:\ )#I  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 1^AG/w  
RandomAccessFile oSavedFile; <Oihwr@5<  
long nPos; Mi:i1i cdn  
),5|Ves;t[  
v0u, :eZ4  
public FileAccessI() throws IOException 91\]Dg  
{ v]c+|nRs  
this("",0); a2SXg A  
} mJ JF  
BI:O?!:9)  
e!oL!Zg  
public FileAccessI(String sName,long nPos) throws IOException xV>sc;PEb  
{ n# "N"6s  
oSavedFile = new RandomAccessFile(sName,"rw"); ,?(U4pzX  
this.nPos = nPos; 9?zi  
oSavedFile.seek(nPos); /j"aOLL|  
} bTc^ huP  
0P^&{ek+)  
X1 FKcWv  
public synchronized int write(byte[] b,int nStart,int nLen) z6uHe{|  
{ *yqke<o9)  
int n = -1; Mt\.?V:  
try{ G0b##-.'^  
oSavedFile.write(b,nStart,nLen); /amWf^z  
n = nLen; fir#5,*q|  
} Q=h37]U+  
catch(IOException e) Wp(Rw4j  
{ a Juv{  
e.printStackTrace (); @j'GcN vs  
} X6so)1jJ  
>Y=qSg>Ik  
|u_fVQj  
return n; 'H-hp   
} FE3uNfQs|  
9=.7[-6i9  
sGO+O$J  
} F!zGk(Pu  
{Lugdf'  
u-@;Q<v$  
/* NS){D7T  
**SiteInfoBean.java ,*Wp$  
*/ %hi]oz  
package NetFox; &?Z<"+B8S  
P1dFoQz  
q+{yv  
public class SiteInfoBean { [E)&dl_k  
[ i8Ju  
0.0r?T  
private String sSiteURL; //Site's URL JQ9+kZ  
private String sFilePath; //Saved File's Path 8f>v[SQ"  
private String sFileName; //Saved File's Name iM M s3  
private int nSplitter; //Count of Splited Downloading File ?\_vqW  
lY[\eQ 1:  
Qb8Z+7  
public SiteInfoBean() o]@'R<F(u  
{//nSplitter的缺省值为5 =}'7}0M_=  
//default value of nSplitter is 5 2?kVbF  
this("","","",5); D*t[5,~j  
} EAV6qW\r5]  
+Ou<-EQV  
g1I8_!}~  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~T!D:2G  
{ @T] G5|\ok  
sSiteURL= sURL; H $mZ?  
sFilePath = sPath; ~toR)=Yv  
sFileName = sName; <4P.B?-/t  
this.nSplitter = nSpiltter; X3HJ3F;==  
]T._TZ"  
TecWv@.  
} ~h$ H@&5  
kH?PEA! \  
g ,yB^^%  
public String getSSiteURL() 0s6eF+bs  
{ rh T!8dTk  
return sSiteURL; 83F]d+n  
} 2]}e4@{  
~?B\+6<V  
*~^%s +b  
public void setSSiteURL(String value) |WSm puf  
{ q#`;G,rs  
sSiteURL = value; YGhHIziI  
} 3935cxT1U  
A_+*b [P  
E//*bmww  
public String getSFilePath() +1Pu29B0  
{ i}@5<&J  
return sFilePath; ~zDFL15w  
} [Vj|fy4  
!X 0 (4^  
^+Njz{rpG  
public void setSFilePath(String value) ZVz*1]}  
{ xLw[ aYy4  
sFilePath = value; ?uXY6J"  
} \b?O+;5Cj  
8KWhXF  
0$|wj^?U  
public String getSFileName() wD SSgk  
{ =6B I[_0  
return sFileName; =<U'Jtu6'  
} ~TjTd  
r]&&*:  
t}gK)"g  
public void setSFileName(String value) 9\i^.2&  
{ ]o`FF="at  
sFileName = value; hcQv!!Q"k$  
} `7'=~BP?X  
qGgdWDn`  
>k(AQW5?  
public int getNSplitter() kaVYe)~  
{ Ms A)Y  
return nSplitter; >|JMvbje  
} 7` t,   
Og kb N`  
CxVrnb[`q  
public void setNSplitter(int nCount) op|x~Thf  
{ bfA9aT  
nSplitter = nCount; Wl3fR[@3Q  
} M:w]g`LKl  
} m\ /V0V\  
G_?qY#"(  
O9F#gO|!  
/* @m"P_1`*  
**Utility.java 92L{be; SY  
*/ 5@~5RNrq2  
package NetFox; IF|%.%I$!U  
S]biN]+7s  
}Yp]A  
public class Utility { 2LH.If  
2graLJ?9Z  
9_pOV%Qs  
public Utility() P87qUC  
{ 6Q9S~YYq  
Q |^c5  
L!kbDbqn  
} Ib$?[  
;EfREfk  
//线程睡眠 kam \dn04  
public static void sleep(int nSecond) !,PoH  
{ a5%IjgQ&z  
try{ T8a!"lPP7  
Thread.sleep(nSecond); Z6oA>D  
} 0G/_"} @  
catch(Exception e) )UG<KcdI  
{ )rv<"  
e.printStackTrace (); 84ma X'  
} 44cy_  
} TzK[:o  
h`/1JjP  
//日志 Toc="F`SW  
public static void log(String sMsg) W>`#`u  
{ [7SR2^uf<j  
System.err.println(sMsg); =%oKYQ  
} j0[9Cj^%c  
KR/SMwy  
d<4q%y'X{  
public static void log(int sMsg) $9O%,U@  
{ 00@y,V_]  
System.err.println(sMsg); Tta+qjr  
} @60/IE{-v  
} -m>ng E~q  
q3R?8Mb  
kc70HrG  
/* 4f> s2I&pQ  
**TestMethod.java BA|*V[HBE  
*/ `1"Xj ^ YM  
package NetFox; w B[H &  
+46?+kKt  
3L(vZ2&  
public class TestMethod { {F+iL&e)  
n:[GK_  
9dD;Z$x&Xk  
public TestMethod() zAdZXa[MRY  
{ ///xx/weblogic60b2_win.exe .m\'|%  
try{ ^{Y9!R*9U*  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0|_d{/VK4  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); au 5qbP  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;p'Ej'E  
fileFetch.start(); 6H}8^'/u  
} Qape DU;  
catch(Exception e){e.printStackTrace ();} G[5z3  
F%>`?NG+c  
3F6=/  
} C!}9[X!7@:  
u|]`gsFZ\  
%t\ ~3pw=  
public static void main(String[] args)  MUd 9R  
{ 'VTLp.~G~  
new TestMethod(); rfS kQT  
} <:UP  
} <v =T31aS  
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