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http断点续传简单实现(java)

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/* L)qDtXd4  
**SiteFileFetch.java  'K7m!y  
*/ 9z9\pXFQ  
package NetFox; &Fg|52  
import java.io.*; j2GTo~muq  
import java.net.*; rQb=/@-  
\fD)|   
_yN&+]c  
public class SiteFileFetch extends Thread { hq|I%>y  
0` y*7.Ip  
FJCLK#-  
SiteInfoBean siteInfoBean = null; //文件信息Bean JOUZ"^v  
long[] nStartPos; //开始位置 mQka?_if)  
long[] nEndPos; //结束位置 km,I75o.  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 !-cK@>.pE  
long nFileLength; //文件长度 GVK c4HGt  
boolean bFirst = true; //是否第一次取文件  n)t'?7  
boolean bStop = false; //停止标志 uK;&L?WB  
File tmpFile; //文件下载的临时信息 D<wz%*  
DataOutputStream output; //输出到文件的输出流 p-o8Ctc?V  
V7}]39m(s  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) L}M%z9K` h  
public SiteFileFetch(SiteInfoBean bean) throws IOException fuQk}OW{  
{ nQaryL  
siteInfoBean = bean; ZR8%h<  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); xMr=tU1C  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); kE`Fg(M  
if(tmpFile.exists ()) 8W"Xdv{  
{ vBLs88  
bFirst = false; /Y#Q<=X  
read_nPos(); `37%|e3bQ  
} 6'[gd  
else ]VcuD05"C  
{ rf=oH }  
nStartPos = new long[bean.getNSplitter()]; N eC]MW  
nEndPos = new long[bean.getNSplitter()]; 57jDsQAj  
} =_=0l+\}  
>z|bQW#2  
zb,YYE1  
dIq*"Ry+~  
} jb83Y>  
eZdFfmYW^R  
'A{B[  
public void run() C-sFTf7  
{ 'Y22HVUX  
//获得文件长度 [R(dCq>  
//分割文件 JKY  
//实例FileSplitterFetch lKBI3oYn  
//启动FileSplitterFetch线程 q5G`N>"V  
//等待子线程返回 x,j%3/J^2  
try{ 3S=$ng  
if(bFirst) dthtWnB@  
{ 's\rQ-TV  
nFileLength = getFileSize(); :2*0Jh3_  
if(nFileLength == -1) @>q4hYF  
{ -,qGEJ  
System.err.println("File Length is not known!"); b`fWT:?=  
} a^eR~efdu@  
else if(nFileLength == -2) "BA&  
{ 9WT{~PGj  
System.err.println("File is not access!"); UXPF"}S2  
} OIY  
else 5h [<!f=  
{ R q .2  
for(int i=0;i<nStartPos.length;i++) f64}#E|w  
{ 4K0Fc^-  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ?W\KIp \Kn  
} 08_<G`r  
for(int i=0;i<nEndPos.length-1;i++) X- P%^mK  
{ 3U9leY'2N  
nEndPos = nStartPos[i+1]; L~!Lq4]V\g  
} 0 } |21YED  
nEndPos[nEndPos.length-1] = nFileLength; ,?c=v`e  
} l{8t;!2t  
} 9/PX~j9O?  
'NN3XyD  
BmFtRbR  
//启动子线程 ^0(`:*  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; q rF:=?`E  
for(int i=0;i<nStartPos.length;i++) G7k.YtW  
{ c|F26$rv  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z|BOuB^   
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9Idgib&  
nStartPos,nEndPos,i); 5|g#>sx>`q  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hY/i)T{  
fileSplitterFetch.start(); !|-:"hE1h  
} g+QNIM>  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), tN_~zP  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :1gcLsF  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >K 7]G?+7E  
nEndPos = " + nFileLength); (Eo#oX  
// fileSplitterFetch[nPos.length-1].start(); D6:"k 2  
fO}Y$y\q  
P,bis7X.  
//等待子线程结束 _Kv;hR>  
//int count = 0; IF kU8EK&B  
//是否结束while循环 *lyRy/POB  
boolean breakWhile = false; y<^hM6S?Z  
W:1GY#Pe  
jF 6[+bW<  
while(!bStop) 66'AaA;0^i  
{ IRbZ ;*3dO  
write_nPos(); r1zuc:W 1  
Utility.sleep(500); x?2y^3<5  
breakWhile = true; (P 9$Ei0fv  
2l}3L  
0c]3 ,#  
for(int i=0;i<nStartPos.length;i++) puK /;nns  
{ Ql9 )  
if(!fileSplitterFetch.bDownOver) #IxCI)!I{[  
{ $`txU5#vs  
breakWhile = false; [p96H)8YU  
break; }^ZPah  
} ca"20NQ)  
} Y4)=D@JI  
if(breakWhile) p2j=73$  
break; jEW@~e  
r~sQdf  
!;B^\ 8{  
//count++; KTjf2/  
//if(count>4) cB4p.iO   
// siteStop(); PHqIfH [  
} ZZU"Q7`^  
' 4 Kf  
W_ubgCB  
System.err.println("文件下载结束!"); 7_]Bu<{f  
} /@9-D 4  
catch(Exception e){e.printStackTrace ();} pd oCV  
} *_tJ;  
k1_ 3\JO"6  
E{E%nXR)  
//获得文件长度 :\,3=suWq  
public long getFileSize() X-J<gI(Y  
{ Ng1uJa[k!d  
int nFileLength = -1; Y?V>%eBu  
try{ ]F1ZeAh5  
URL url = new URL(siteInfoBean.getSSiteURL()); S<DS|qOo  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >TwL&la  
httpConnection.setRequestProperty("User-Agent","NetFox"); P*6&0\af|  
M UqV$#4@I  
)Tj\ym-Vl  
int responseCode=httpConnection.getResponseCode(); J2Eb"y>/;  
if(responseCode>=400) -,} ppTG  
{ 'E~[I"0  
processErrorCode(responseCode); 2Ls  
return -2; //-2 represent access is error \7A6+[ `fa  
} roE*8:Y  
*m`KY)b=l  
Auf2JH~  
String sHeader; jl~?I*Gr  
wEJ?Y8  
($Y6hn+  
for(int i=1;;i++) a%)-iL X8&  
{ "ju0S&  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); R{A$hnhW6  
//Utility.log(in.readLine()); %SD=3UK6  
sHeader=httpConnection.getHeaderFieldKey(i); %2TjG  
if(sHeader!=null) U#1 ,]a\  
{ 06~HVv  
if(sHeader.equals("Content-Length")) d=8q/]_p  
{ u7kw/_f  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); psZ #^@>mJ  
break; tQrkRg(E:  
} xbhU:,o  
} cQldBc  
else l]v>PIh~N  
break; Rjz~n38.  
} :Vx5%4J  
} RE}$(T=  
catch(IOException e){e.printStackTrace ();} ({#M*=&"  
catch(Exception e){e.printStackTrace ();} i& ybvTl  
(lR9x6yf  
<X1^w  
Utility.log(nFileLength); h?ZxS  
x"QZ}28(t  
[p# }=&d  
return nFileLength; yZ]u{LJS  
} JJ$q*  
a'2^kds  
CN, oH4IU  
//保存下载信息(文件指针位置) ]:vo"{*C  
private void write_nPos() &o$Pwk\p/  
{ enJgk(  
try{ 6!^&]4  
output = new DataOutputStream(new FileOutputStream(tmpFile)); QSq0{  
output.writeInt(nStartPos.length); v\:P _J  
for(int i=0;i<nStartPos.length;i++) m'P,:S)=  
{ { |[n>k   
// output.writeLong(nPos); aZ{]t:]  
output.writeLong(fileSplitterFetch.nStartPos); I?!7]Sn$  
output.writeLong(fileSplitterFetch.nEndPos); k(.6K[ b  
} 1y($h<  
output.close(); /vLdm-4  
} D!d1%hac  
catch(IOException e){e.printStackTrace ();} 2[qlEtvQ  
catch(Exception e){e.printStackTrace ();}  +*aZ9g  
} *eonXJYD  
Juqe%he`  
8Cw+<A*  
//读取保存的下载信息(文件指针位置) U%nLo[k  
private void read_nPos() u+Q<> >lU  
{ a2'f#[as  
try{ ,aBo p#  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >=Pn\" j  
int nCount = input.readInt(); :v>Nz7SB  
nStartPos = new long[nCount]; z<c%Xl\$%  
nEndPos = new long[nCount]; .V Cfh+*J#  
for(int i=0;i<nStartPos.length;i++) ^yo~C3 r~  
{ $ 'obj  
nStartPos = input.readLong(); T,D(Xh  
nEndPos = input.readLong(); CFU'- #b  
} 96FS-`  
input.close(); z nxAP|  
} ')mR87  
catch(IOException e){e.printStackTrace ();} jA}b=c  
catch(Exception e){e.printStackTrace ();} yhpeP  
} p\ }Ep  
vz-O2B_u  
$+$S}i=  
private void processErrorCode(int nErrorCode) ,=@%XMS  
{ O.% $oV  
System.err.println("Error Code : " + nErrorCode); :]hNw1e  
} J*} warf&  
s}3`%?,6y  
m=hUHA,p4  
//停止文件下载 qXw^y  
public void siteStop() Ob#d;F  
{ TppuEC>  
bStop = true; fT.GYvt`  
for(int i=0;i<nStartPos.length;i++) ]'iOV-2^'  
fileSplitterFetch.splitterStop(); q&RezHK l  
C6T?D5  
T7bD t  
} b&j}f  
} RU_wr<  
//负责部分文件的抓取 0;V "64U  
**FileSplitterFetch.java / !@@  
*/ Adma~]T9  
package NetFox; L" GQ Q  
=W_Pph  
d~F4  
import java.io.*; .*(xkJI3  
import java.net.*; 4Lb!Au|Y  
~0 Ifg_G  
GWvw<`4  
public class FileSplitterFetch extends Thread { 0mMoDJRy  
%qYiE!%&  
t3// U#  
String sURL; //File URL Glw_<ag[  
long nStartPos; //File Snippet Start Position qTuQ]*[-  
long nEndPos; //File Snippet End Position miTySY6 ^  
int nThreadID; //Thread's ID ~>"m`Q&[  
boolean bDownOver = false; //Downing is over zvgy$]y'\  
boolean bStop = false; //Stop identical !Enq2  
FileAccessI fileAccessI = null; //File Access interface Ump$N#  
gZHuyp(B  
:+q d>;yf#  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Y*Ra!]62  
{ ls*bCe  
this.sURL = sURL; H6t'V%Ys  
this.nStartPos = nStart; \QvoL  
this.nEndPos = nEnd; wJ%;\06  
nThreadID = id; ,ut-Di=6  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 CVt:tV  
} ^tTASK  
Nr,Q u8  
cM hBOm*  
public void run() rijavZS6  
{ V*< `!w  
while(nStartPos < nEndPos && !bStop) qbsmB8rh  
{ y<5RV>"Vg  
u$38"&cmA  
!ay:h Iv  
try{ o^ zrF  
URL url = new URL(sURL); y9)w(y !  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pv[Gg^  
httpConnection.setRequestProperty("User-Agent","NetFox"); !Soz??~o/  
String sProperty = "bytes="+nStartPos+"-"; je`Ysben  
httpConnection.setRequestProperty("RANGE",sProperty); JJZu%9~[  
Utility.log(sProperty); rLpfybu  
N xW Dw  
ki6L t  
InputStream input = httpConnection.getInputStream(); h0O t>e"  
//logResponseHead(httpConnection); b$;qtfJG  
\5iMr[s  
{)jTq??  
byte[] b = new byte[1024]; }] p9  
int nRead; Fc6o6GyL|o  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Ls` [7w  
{ 0H/)wy2ym  
nStartPos += fileAccessI.write(b,0,nRead); d@XXqCR<  
//if(nThreadID == 1) U #C@&2  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ak A7))Q  
} SNJSRqWL/  
dM=45$\q  
tiGBjTPt  
Utility.log("Thread " + nThreadID + " is over!"); jP{&U&!i  
bDownOver = true; yiw4<]{IX  
//nPos = fileAccessI.write (b,0,nRead); `+m:@0&L  
} abD@0zr  
catch(Exception e){e.printStackTrace ();} lDSF  
} 5MCnGg@  
} ve]hE}o/}  
dfP4SJqq  
@9tzk [  
//打印回应的头信息 lQM&q  
public void logResponseHead(HttpURLConnection con) sg8[TFX@Z  
{ hm*cGYV/  
for(int i=1;;i++) *\(MG|S  
{ ~ \]?5 nj  
String header=con.getHeaderFieldKey(i); V1&qgAy~  
if(header!=null) L</k+a?H!  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); RY .@_{  
Utility.log(header+" : "+con.getHeaderField(header)); .He}f,!f<  
else ^6On^k[|fw  
break; l0 8vF$k|d  
} xG(xG%J  
} bu9.Hv T'  
GXp`yK9c  
'Qh1$X)R7a  
public void splitterStop() T-LX>*  
{ kV+%(Gl8  
bStop = true; c'.XC}  
} 2 EWXr+IU.  
bp!Jjct  
O9C&1A|lA  
} eaAGlEW6J  
[ {$%9lm  
Bd]k]v+  
/* /%mT2  
**FileAccess.java ;1HzY\d%<  
*//文件访问(定位,写) ]rG/?1'^i  
package NetFox; /9e?uC6  
import java.io.*; n$F~  
Fw S>V2R  
9=mc3m:Tb(  
public class FileAccessI implements Serializable{ 1<tJ3>Xl  
i!x>)E  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 en'"" w  
RandomAccessFile oSavedFile; wRvh/{xB  
long nPos; =EYWiK77a  
[l3ys  
<5? pa3  
public FileAccessI() throws IOException o_1N "o%  
{ ]rv4O@||w  
this("",0); Z5E; FGPb  
} E.Q]X]q  
AhD C5ue=  
sH.=Faos  
public FileAccessI(String sName,long nPos) throws IOException z %Bzf~N9  
{ @c-  
oSavedFile = new RandomAccessFile(sName,"rw"); W6Mq:?+D  
this.nPos = nPos; '4nJ*Xa  
oSavedFile.seek(nPos); D#AqZS>B  
} kU+|QBA@  
Zwm/c]6`  
W#%s0EN<_  
public synchronized int write(byte[] b,int nStart,int nLen) f1]zsn:  
{ lxm/*^  
int n = -1; R8cOb*D  
try{ D<m0G]Ht*  
oSavedFile.write(b,nStart,nLen); X@"G1j >/  
n = nLen; mU]VFPr5  
} [ /YuI@C,@  
catch(IOException e) \ )=WA!  
{ wk ^7/B  
e.printStackTrace (); {fnx=BaG  
} W|D kq  
m`l9d4p w?  
FJDE48Vi  
return n; <sw@P":F  
} "(3u)o9  
f"KrPx!^b  
\XPGA uEo  
} <^\rv42'(2  
j)2I+[aoB  
T8|5%Y  
/* &iInru3  
**SiteInfoBean.java D8<C7  
*/ 37$ ^ie)  
package NetFox; A*eVz]i,k&  
*I)J%#  
>v%js!`f  
public class SiteInfoBean { J09jBQ] R  
y ?&hA! x  
kzjuW  
private String sSiteURL; //Site's URL =KUmvV*\  
private String sFilePath; //Saved File's Path a3>/B$pE  
private String sFileName; //Saved File's Name :{#O   
private int nSplitter; //Count of Splited Downloading File odSPl{.>d  
G0{Z@CvO'  
>UMxlvTg&  
public SiteInfoBean() 4SZ,X^]I>  
{//nSplitter的缺省值为5 1vxRhS&FY  
//default value of nSplitter is 5 P+0'^:J  
this("","","",5); Lx wi"ndP  
} eD?&D_l~6  
ly-(F2  
W;'fAohr  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) E?G'F3i  
{ J7* o%W*V  
sSiteURL= sURL; u MEM7$o  
sFilePath = sPath; b!P,+!<  
sFileName = sName; CtXbAcN2B  
this.nSplitter = nSpiltter; V6X )L>!xx  
'< U&8?S  
-BH/)$-$  
} O|V0WiY<  
!,$#i  
J(l\VvK  
public String getSSiteURL() :YI5O/gsk?  
{ $Lr& V~  
return sSiteURL; 4AS%^&ah  
} zak\%yY`  
,7LfvZj4[  
B;r_[^  
public void setSSiteURL(String value) 2ZY$/  
{ &em~+83  
sSiteURL = value; W;Y^(f  
} :$$~$P  
nbF<K?  
}6@E3z]AMO  
public String getSFilePath() hBjU(}\3  
{ ZC N}iQu4  
return sFilePath; LUbj^iQ9  
} %dzt'uz  
TP rq:"K  
NX& dJ 6a  
public void setSFilePath(String value) He(65ciT<O  
{ Jy)=TJ!y  
sFilePath = value; Nvgi&iBh8  
} i%-yR DIX  
Q>,&@  
z2iMpZ  
public String getSFileName() (oG YnN,2  
{ xoKK{&J  
return sFileName; Byc;r-Q5V  
} J'}+0mln  
]p`y  
l8FJ\5'M  
public void setSFileName(String value) 5vyg-'  
{ s<zN`&t  
sFileName = value; lxyTh'  
} )8A.Wg4S;c  
!:&SfPv  
+]eG=. u  
public int getNSplitter() M-nRhso  
{ i1cd9  
return nSplitter; 0vqVE]C  
} J\y^T3Z  
I=kqkuW  
O>' }q/  
public void setNSplitter(int nCount) 1 pVw,}  
{ .;4N:*hY  
nSplitter = nCount; 9^XZ|`  
} ^I!Z)/  
} tnJ7m8JmC  
O2Qmz=%  
MJ JC6:  
/* [P &B  
**Utility.java EHwb?{  
*/ klUV&O+=%  
package NetFox; FOQ-KP\ =,  
[c3!xHt5O  
3Y)&[aj  
public class Utility { }_nBegv  
rRRh-%.RU  
.V hU:_u  
public Utility() .b,\.0N  
{ JKZVd`fF  
G`!,>n 3  
j2D!=PK;  
} sE?%;uBb  
OkciL]  
//线程睡眠 %unn{92)  
public static void sleep(int nSecond) @} r*KF-  
{ PaaMh[OmG  
try{ B~I ]3f  
Thread.sleep(nSecond); ,7B7X)m{3  
} P8YnKyI,.  
catch(Exception e) BQ6$T&  
{ 6]1RxrAV  
e.printStackTrace (); L ci?  
} -dM~3'  
} B&_:20^y~  
\^(#b,k#  
//日志 }rJqMZ]w  
public static void log(String sMsg) 6|EOB~|  
{ -9om,U`t  
System.err.println(sMsg); R|RGoGE6g  
} MGF !ZZ\  
JPDxzp  
lf( +]k30  
public static void log(int sMsg) wrkw,H  
{ P'Y(f!%  
System.err.println(sMsg); spA|[\Nl  
} 96\FJHt Z  
} $*{,Z<|2  
;l;jTb^l  
%g7j7$c  
/* 16Qu{K  
**TestMethod.java )j8'6tk)Z  
*/ oc"p5Y3,Os  
package NetFox; 'gN[LERT  
tV=Qt[|@  
?*~ ~Ok  
public class TestMethod { [\ku,yd%0  
$(62j0mS>  
;rf{T[i  
public TestMethod() >7WT4l)7!b  
{ ///xx/weblogic60b2_win.exe .Yk}iHcW.  
try{ F7}yt  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5i6Ji(  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ) P7oL.)  
SiteFileFetch fileFetch = new SiteFileFetch(bean); \ ERBb.  
fileFetch.start(); w?D=  
} A@3'I  ;  
catch(Exception e){e.printStackTrace ();} 'cCM[P+  
ar@,SKU'K  
~[!Tpq5  
} d*TH$-F!p  
yHY2 SXm  
_Q #[IH9  
public static void main(String[] args) [p4([ef '  
{ #IppjaPl8  
new TestMethod(); CM~x1f*v  
} {v!w2p@  
} v1$}[&/  
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