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http断点续传简单实现(java)

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/* '0Zm#g  
**SiteFileFetch.java Xu]h$%W  
*/ hPPB45^  
package NetFox; `` -k{C#F  
import java.io.*; zUQe0Gc.b^  
import java.net.*; AP@<r  
a;&}zcc*  
vXubY@k2  
public class SiteFileFetch extends Thread { ??I:H  
jaqV[*440U  
 4Iq5+Q  
SiteInfoBean siteInfoBean = null; //文件信息Bean 4g!7 4a  
long[] nStartPos; //开始位置 F!R2_89iy  
long[] nEndPos; //结束位置 n#>5?W  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 `cO|RhD @  
long nFileLength; //文件长度 no3Z\@%  
boolean bFirst = true; //是否第一次取文件 *:#Z+7x ]  
boolean bStop = false; //停止标志 Qu}N:P9l?X  
File tmpFile; //文件下载的临时信息 %]GV+!3S  
DataOutputStream output; //输出到文件的输出流 Vi,Y@+4  
Y`]rj-8f0B  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ,eK2I Ao  
public SiteFileFetch(SiteInfoBean bean) throws IOException q2Rf@nt  
{ $`Rxn*}V4#  
siteInfoBean = bean; ;@!;1KDy  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); VKf6|ae  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); BvI 0v:  
if(tmpFile.exists ()) #ko6L3Pi  
{ sy.:T]ZH  
bFirst = false; cKpQr7]ur  
read_nPos(); 28+HKbgK  
} @H4wHlb  
else z `@z  
{ 82 .HH5Z{  
nStartPos = new long[bean.getNSplitter()]; EOQaY  
nEndPos = new long[bean.getNSplitter()]; w 06gY  
} #W^_]Q=5R'  
'8={ sMy  
Fva]*5  
S| "TP\o  
} PHl4 vh#E!  
R25-/6_V>  
GDmv0V$6  
public void run() W+/2c4$F3  
{  h.D^1  
//获得文件长度 r"[L0Cbb  
//分割文件 i]@c.Q iFN  
//实例FileSplitterFetch wKLN:aRF2  
//启动FileSplitterFetch线程 .> ,Z k S  
//等待子线程返回 :P"9;$FY  
try{ :1NYpsd.i  
if(bFirst) 5IO3 %p?  
{ _;V YFs  
nFileLength = getFileSize(); .Map   
if(nFileLength == -1) K_FBy  
{ Y}ky/?q  
System.err.println("File Length is not known!"); @QX4 \  
} c*jr5 Y  
else if(nFileLength == -2) acy"ct*I  
{ AD,@,|A  
System.err.println("File is not access!"); _&=9Ke  
} ?9qAe  
else 65t[vi*C  
{ Ul9b.`6  
for(int i=0;i<nStartPos.length;i++) =3pD:L  
{ Lm.Ik}Gli  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); fW[_+r]  
} ?Cc$]  
for(int i=0;i<nEndPos.length-1;i++) x;*VCs  
{ lvG3<ls0K$  
nEndPos = nStartPos[i+1]; . *Z#cq0  
} TiTYs  
nEndPos[nEndPos.length-1] = nFileLength; 0x6@{0  
} )biX8yq hR  
} /T{mS7EpYc  
sbpu qOL  
,qYf#fU#7  
//启动子线程 ={OCa1  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; KM EXT$p  
for(int i=0;i<nStartPos.length;i++) gMCy$+?  
{ a3*.,%d  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _5Bu [I  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <)"iL4 kDI  
nStartPos,nEndPos,i); )~G8 LZ  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); NCp%sGBmG  
fileSplitterFetch.start(); x9 TuweG  
} cFe V?a  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;,R[]B01u  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); E=3#TBd  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \?[O,A  
nEndPos = " + nFileLength); Jr|K>  
// fileSplitterFetch[nPos.length-1].start(); YALyZ.d  
w:n(pLc<  
Un~]Q?w  
//等待子线程结束 z)r8?9u  
//int count = 0; \gjl^# ;  
//是否结束while循环 Y{`3`Pg&N  
boolean breakWhile = false; qNhH%tYQ  
P: jDB{  
7Z9.z 4\  
while(!bStop) "hJ7 Vv_  
{ {P,>Q4N  
write_nPos(); aS2a_!f  
Utility.sleep(500); 8U8P g2  
breakWhile = true; JB641nv  
L)@`58Eil  
g6HphRJ5s  
for(int i=0;i<nStartPos.length;i++) T,A!5V>cX  
{ 5R& x{jf$  
if(!fileSplitterFetch.bDownOver) |)~Ex 9%ev  
{ wbn^R'  
breakWhile = false; 7cy+Nz  
break; Fa6H(L3  
} j'#)~>b  
} 9@JlaY)0  
if(breakWhile) "K/[[wX\b  
break; +?ws !LgF  
U;^CU!a  
j0Id!o  
//count++; S5zpUF=  
//if(count>4) CD*f4I#d  
// siteStop(); f6@^ Mg  
} ]:[)KZ~  
))8Emk^Q{  
)zo#1$C-  
System.err.println("文件下载结束!"); = E##},N"  
} L.R"~3  
catch(Exception e){e.printStackTrace ();} IS3e|o*]MP  
} U]+b` m  
GG@iKL V  
d<e+__ 2  
//获得文件长度 {Q}!NkF 1  
public long getFileSize() U&tfl/  
{ yd\5Z[iEp  
int nFileLength = -1; Krt$=:m|1  
try{ f>.` xC{  
URL url = new URL(siteInfoBean.getSSiteURL()); 7Y$4MMNQ  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); UUt~W  
httpConnection.setRequestProperty("User-Agent","NetFox"); ZJiuj!  
$`-SVC  
1jR=h7^=  
int responseCode=httpConnection.getResponseCode(); S.zg&   
if(responseCode>=400) ,<R>Hiwg/s  
{ WRN8#b  
processErrorCode(responseCode); WsG"x>1n  
return -2; //-2 represent access is error 7-g]A2N  
} $%N;d>[U,  
3sd{AkD^  
P2A]qX  
String sHeader; 5WrIg(l  
O6*'gnke  
* ePDc'   
for(int i=1;;i++) \<0G kp  
{ FN{H\W1cf  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); xkk@ {}J\  
//Utility.log(in.readLine()); Qivf|H619  
sHeader=httpConnection.getHeaderFieldKey(i); G.A=hGw  
if(sHeader!=null) SaX,^_GY  
{ lo IL{2  
if(sHeader.equals("Content-Length")) 0R2S@4%Y  
{ bn^mL~  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); -N /8Ho  
break; }.fZy&_  
} "t3uW6&  
} tal>b]B;  
else $9LGdKZ_D  
break; B;Q`vKY  
} yoq\9* ?u^  
} YD0vfwh  
catch(IOException e){e.printStackTrace ();} yBXkN&1=%;  
catch(Exception e){e.printStackTrace ();} =|j*VF2y"  
(6b?ir~  
!3b|*].B  
Utility.log(nFileLength); I{*.htt{  
tkm~KLWV&7  
s K""  
return nFileLength; -$sl!%HO%  
} &sr:\Qn X/  
PU]7c2.y  
5p#o1I  
//保存下载信息(文件指针位置) iZDb.9@&t  
private void write_nPos() !>a&`j2:W  
{  8o%<.]   
try{ df21t^0/  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~:ub  
output.writeInt(nStartPos.length); U#UVenp@  
for(int i=0;i<nStartPos.length;i++) Kd AR)EU>  
{ )eTnR:=  
// output.writeLong(nPos); nsr _\F\  
output.writeLong(fileSplitterFetch.nStartPos); @4W\RwD  
output.writeLong(fileSplitterFetch.nEndPos); di)noQXkB-  
} L:k@BCQM  
output.close(); 7>W+Uq  
} 9}'l=b:Jms  
catch(IOException e){e.printStackTrace ();} WNF=NNO-R  
catch(Exception e){e.printStackTrace ();} W_e-7=6  
} "W,"qFx  
?h>%Ix  
.5Z,SGBf  
//读取保存的下载信息(文件指针位置) H$=h-  
private void read_nPos() pDq^W @Rq  
{ b3y,4ke"  
try{ Ca`/t8=  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |2+F I<v4  
int nCount = input.readInt(); {=pP`HD0  
nStartPos = new long[nCount]; z</XnN  
nEndPos = new long[nCount]; N~Sue  
for(int i=0;i<nStartPos.length;i++) ~,`\D7Z3  
{ YDZ1@N}^B  
nStartPos = input.readLong(); L&3Ar'  
nEndPos = input.readLong(); !)51v {  
} W~+!"^<n  
input.close(); g[D,\  
} VQG  /g\  
catch(IOException e){e.printStackTrace ();} q6m87O9  
catch(Exception e){e.printStackTrace ();} pO7{3%  
} 4/mj"PBKL  
vt(}ga  
F_M~!]<na  
private void processErrorCode(int nErrorCode) mXN1b!  
{ =E6i1x%j  
System.err.println("Error Code : " + nErrorCode); yo Q?lh  
} wZ\e3H z  
n_!]B_Vd$  
([4{n  
//停止文件下载 _6QLnr&@j  
public void siteStop() Fm[?@Z&wP  
{ A]~iuUHm  
bStop = true; Do[ F+Y  
for(int i=0;i<nStartPos.length;i++) a s<q  
fileSplitterFetch.splitterStop(); Tr}$Pb1  
^JF_;~C  
|Z^c #R  
} V"Y Fu^L  
} _ /2 8Cw  
//负责部分文件的抓取 q%=7<( w  
**FileSplitterFetch.java oRJP5Y5na  
*/ M@LaD 5  
package NetFox; U~zN*2-  
iYfLo">  
l.NkS   
import java.io.*; ,*}g r  
import java.net.*; $0`$)(Y  
k~s>8N:&G  
/xm} ?t0U  
public class FileSplitterFetch extends Thread { K&gc5L  
JXR/K=<^  
L!}j3(I  
String sURL; //File URL 5\*wX.wp  
long nStartPos; //File Snippet Start Position 2" {]A;@  
long nEndPos; //File Snippet End Position !A^w6Q;`V  
int nThreadID; //Thread's ID 2O)Kn q  
boolean bDownOver = false; //Downing is over RxDxLU2kt  
boolean bStop = false; //Stop identical yfw>y=/p  
FileAccessI fileAccessI = null; //File Access interface RT+30Q?  
%[ bO\,  
}zfLm` vJ  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException yOCcp+`T}  
{ 4`5Qt=}  
this.sURL = sURL; E,yzy[gl  
this.nStartPos = nStart; Vwh&^{Eh  
this.nEndPos = nEnd; z&yb_A:>  
nThreadID = id; z1KC$~{O  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 u{lDof>  
} /*p?UW<*4  
*$Wx*Jo  
Kd[`mkmS  
public void run() ,DUQto  
{ 2Z9gOd<M~  
while(nStartPos < nEndPos && !bStop) G|Yp <W%o  
{ Px?At5  
~aq?Kk  
2] wf`9ZH  
try{ Q{|'g5(O  
URL url = new URL(sURL); `::(jW.KO  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); UeiJhH,u   
httpConnection.setRequestProperty("User-Agent","NetFox"); wbF1>{/"  
String sProperty = "bytes="+nStartPos+"-"; L"vG:Mq@D  
httpConnection.setRequestProperty("RANGE",sProperty); ^)P5(fJ  
Utility.log(sProperty); I8oKa$RF  
AiHDoV+-  
'*{Rn7B5  
InputStream input = httpConnection.getInputStream(); 1X_!%Z  
//logResponseHead(httpConnection); \w\47/k{  
-N!soJ<  
2dJ)4  
byte[] b = new byte[1024]; `r0 qn'*  
int nRead; n7!Lwq2  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) % |Gzht\  
{ X|lmH{kf  
nStartPos += fileAccessI.write(b,0,nRead); -clg 'Aa;.  
//if(nThreadID == 1) N*)8L[7_;  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \]:NOmI^'  
} ghd[G}  
j tkPi)QR  
`[u>NEb  
Utility.log("Thread " + nThreadID + " is over!"); i@?<]n  
bDownOver = true; D@ 1^:'$V  
//nPos = fileAccessI.write (b,0,nRead); H.G^!0j;  
} ia.B@u1/  
catch(Exception e){e.printStackTrace ();} [&}<! :9'  
} FbNQ  
} k)t8J\  
M]zNW{Xt  
uC ;PP=z  
//打印回应的头信息 Evgq}3  
public void logResponseHead(HttpURLConnection con) 0JL6EL>_  
{ <y/AEY1  
for(int i=1;;i++) T1W9@9,s  
{ vh.tk^&  
String header=con.getHeaderFieldKey(i); "YU~QOGx@  
if(header!=null) X1QZEl  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); k#G7`dJl  
Utility.log(header+" : "+con.getHeaderField(header)); (dnc7KrM  
else K]Cs2IpI  
break; iK0J{'  
} >bP7}T  
} JWjp<{Q; 1  
+uXnFf d^  
"JGig!9  
public void splitterStop() +GtGyp  
{ ^7<mlr  
bStop = true; &y wY?ox  
} e~[z]GLO%  
d33Nx)No  
7027@M?A?  
} `5jB|r/  
~g|0uO}.  
B{7/A[$%C  
/* &=O1Qg=K  
**FileAccess.java AS^$1i:  
*//文件访问(定位,写) /3%xQK>%  
package NetFox; ~4gKA D  
import java.io.*; zC;lfy{f=  
e[o ;l  
C8zeqS^N  
public class FileAccessI implements Serializable{ 9uoj3Rh<  
B>2 1A9&  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5!fW&OiY  
RandomAccessFile oSavedFile; vy y\^nL  
long nPos; N>\?Aeh  
JNCtsfd  
w:(7fu=  
public FileAccessI() throws IOException ExU|EN-  
{ 8ngf(#_{_n  
this("",0); m*,[1oeG&  
} 4?uG> ;V  
UwT$IKR  
[`dipLkr  
public FileAccessI(String sName,long nPos) throws IOException YhR"_  
{ ,QAp5I%3=  
oSavedFile = new RandomAccessFile(sName,"rw"); Y}z?I%zL  
this.nPos = nPos; Oj\mkg  
oSavedFile.seek(nPos); OEi9 )I  
} Qj[O$L0 $  
4'| :SyOm  
5W-M8dc6  
public synchronized int write(byte[] b,int nStart,int nLen) ;itg>\ p3  
{ rmJ847%y`  
int n = -1; <Wq{ V;$  
try{ /hR]aw  
oSavedFile.write(b,nStart,nLen); Mc^7FWkw  
n = nLen; ?LM'5  
} mSeN M  
catch(IOException e) '~a$f;: Dv  
{ 2 ZXF_ o  
e.printStackTrace (); h%e!f#  
} BBj"}~da  
C{^@.8:  
rJj~cPwL"  
return n; z5w|+9U  
} .q}k  
>xgd<  
zt}p-U2I  
} 8iA(:Tb  
g+*[CKO{  
YNk|UwJi  
/* ZM!~M>B9R  
**SiteInfoBean.java uMZf9XUE  
*/ W<l(C!{  
package NetFox; brot&S2P><  
T6#GlO)8)  
JFdzA  
public class SiteInfoBean { [)u{-  
:E*U*#h/  
NWj@iyi<  
private String sSiteURL; //Site's URL C =U4|h~W  
private String sFilePath; //Saved File's Path 4/_|Qy  
private String sFileName; //Saved File's Name $Bb/GXn{\  
private int nSplitter; //Count of Splited Downloading File LXl! !i%  
[hbIv   
pQ8+T|0x  
public SiteInfoBean() GrC")Z|3u  
{//nSplitter的缺省值为5 7C^ nk z  
//default value of nSplitter is 5 OSk9Eb4ld  
this("","","",5); h (2k;M^s  
} gp2)35  
{*Pp^ r  
![%,pip2/&  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b"9,DQB=i  
{ N4-J !r@#~  
sSiteURL= sURL; ,iUx'U  
sFilePath = sPath; l0)uu4|  
sFileName = sName; #m>mYp8E.5  
this.nSplitter = nSpiltter; q5PYc.E([  
3}Qh`+Yj]  
K4~O x  
} 5Bo)j_Qo  
Z]d]RL&r  
9f`Pi:*+/  
public String getSSiteURL() q#Vf2U55m  
{ O!tD1^O!1}  
return sSiteURL; :_ox8xS4  
} 3s2M$3r)6  
,pz CJ@5  
*Cw2h  
public void setSSiteURL(String value) SGm? "esEt  
{ 4uA^/]ygo  
sSiteURL = value; (=9&"UH  
} c2/HY8ttRD  
#J_i 5KmXJ  
^ EOjq  
public String getSFilePath() -&}E:zoe  
{ 0 HmRl  
return sFilePath; Q2Rj0E`  
} )/'s& D  
^cm^JyS)  
ri ~2t3gg  
public void setSFilePath(String value) z^.0eP8\j  
{ y rk#)@/m  
sFilePath = value; flqTx)xE  
} 5@ug1F&   
wn&2-m*a  
mZyTo/\0  
public String getSFileName() .EO1{2=  
{ L8ke*O$  
return sFileName; q0wVV  
} (6nw8vQ  
HenJlo  
~@lNBF  
public void setSFileName(String value) F04Etf 2k  
{ at!?"u  
sFileName = value; :F&WlU$L  
} )w-?|2-w5  
CCV~nf  
C#>C59  
public int getNSplitter() tUQ)q  
{ d/1XL[&  
return nSplitter; s9iM hCu|  
} \BL9}5y  
@#apOoVW>  
SCij5il%  
public void setNSplitter(int nCount) VzesqVx  
{ 5oS\uX|  
nSplitter = nCount; o6 /?WR9  
} VM[8w`  
} @d\F; o<  
"|if<hx+  
3nO|A: t  
/* n>WS@b/o  
**Utility.java tF|bxXs Z  
*/ h.*|4;  
package NetFox; (agdgy:#  
.FUE F)  
;/@R{G{+~;  
public class Utility { 2olim1  
9[`6f8S_$  
I1g u<a  
public Utility() }wV rmDh \  
{ !T*izMX}  
9=|5-? ^  
!r<7]nwV  
} lK-I[i!  
PO&`r r  
//线程睡眠 f@0`,  
public static void sleep(int nSecond) }MNm>3  
{ cF6|IlhO  
try{ jkq+j^  
Thread.sleep(nSecond); isjkfl-!  
} DjIs"5Iei  
catch(Exception e) ~J|0G6H  
{ V;"'!dVX  
e.printStackTrace (); nFqMS|EN  
} LdOB[W  
} Dng^4VRd  
>qE$:V "_5  
//日志 t`  Sh!e  
public static void log(String sMsg) U&6f}=v C  
{ :|a[6Uwl\V  
System.err.println(sMsg); ydt1ED0Q-  
} QUt!fF@t  
157X0&EX  
pPE4~g 05h  
public static void log(int sMsg) <~d N23)  
{ 4P8:aZM  
System.err.println(sMsg); y ;;@T X  
} .eE5pyw+C  
} $)U RY~;i  
gnQd#`  
STI8[e7{  
/* >2a~hW|,  
**TestMethod.java Sz =z TPnO  
*/ n#*cVB81  
package NetFox; f =Nm2(e  
MYjCxy-;A  
O%Mh g\#B  
public class TestMethod { n3(HA  
fc91D]c  
tm$3ZzP4  
public TestMethod() .MKxHM7  
{ ///xx/weblogic60b2_win.exe Fq8Z:;C8  
try{ [(C lvGx  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); KLX>QR@  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 99`xY$  
SiteFileFetch fileFetch = new SiteFileFetch(bean); iY="M_kQ_  
fileFetch.start(); e*tOXXY1  
} r <U }lK  
catch(Exception e){e.printStackTrace ();} MStaP;|  
ek9%Xk8  
]?^mb n  
} ,q4Y N-3  
D3]_AS&\  
W|:WAxJ*d  
public static void main(String[] args) ||hd(_W8  
{ aePk^?KbB  
new TestMethod(); *`kh}  
} !>M: G:K  
} d/MMPge3  
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