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http断点续传简单实现(java)

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/* i7i|370  
**SiteFileFetch.java {E;2&d  
*/ ^2C0oX  
package NetFox; XRClBTKF  
import java.io.*; x>U1t!'  
import java.net.*; EC^Ev|PB\u  
b24NL'jm  
%'RI 3gy  
public class SiteFileFetch extends Thread { FE0qw1{qQ  
HiQoRk  
fBHkLRFH  
SiteInfoBean siteInfoBean = null; //文件信息Bean = 4BLc  
long[] nStartPos; //开始位置 sN6 0o 7.  
long[] nEndPos; //结束位置 6V.awg,  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 8#X?k/mzU  
long nFileLength; //文件长度 l81&[  
boolean bFirst = true; //是否第一次取文件 6(ka"Vu~  
boolean bStop = false; //停止标志 L@)b%Q@a  
File tmpFile; //文件下载的临时信息 R59e&   
DataOutputStream output; //输出到文件的输出流 3~cS}N T  
VQ1?Db(_2  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) 54`bE$:+  
public SiteFileFetch(SiteInfoBean bean) throws IOException Bpk@{E9  
{ H arFo  
siteInfoBean = bean; 3X88x-3  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); *,O :>Z5I  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); +O;OSZ  
if(tmpFile.exists ()) X{0ax.  
{ }}kS~ w-#  
bFirst = false; a) I=U [  
read_nPos(); `ENlV9  
} UgF)J  
else %Nwyx;>9^K  
{ )![f\!'PI  
nStartPos = new long[bean.getNSplitter()]; n/KI"qa]9  
nEndPos = new long[bean.getNSplitter()]; I ybl;u  
} &*jxI[  
[_g#x(=  
1TK #eU  
,Hik(22  
} IeR l6r%:  
""25ay  
E[SV*1)  
public void run() O vyB<r  
{ wc<2Uc  
//获得文件长度 t-v^-#  
//分割文件 LV}UBao5n  
//实例FileSplitterFetch OhSt6&+  
//启动FileSplitterFetch线程 |%M{k A-  
//等待子线程返回 sYAG,r>h  
try{ bqZ?uvc3  
if(bFirst) O4 +SD  
{ adRNrt*!  
nFileLength = getFileSize(); r6O7&Me<  
if(nFileLength == -1) '<R B  
{ q3,P|&T  
System.err.println("File Length is not known!"); ,xAM[h&  
} %4|n-`:  
else if(nFileLength == -2) _'?8s6 H  
{ hO+O0=$}wN  
System.err.println("File is not access!"); -(4E  
} MFc=B`/X  
else !7O=<  
{ yS:IRI.  
for(int i=0;i<nStartPos.length;i++) FT|/ WZR  
{ 9,iq"dQ  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); eHF(,JI  
} R` I8Ud4=  
for(int i=0;i<nEndPos.length-1;i++) C }h<ldlY  
{ L]/\C{}k  
nEndPos = nStartPos[i+1]; wzNt c)~i  
} =\ti<  
nEndPos[nEndPos.length-1] = nFileLength; "6I-]:K-  
} nJ'>#9~a'>  
} VurP1@e&  
#VQGN2bK.  
'-nuH;r  
//启动子线程 Ovaj":L  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3]:p!Y`$  
for(int i=0;i<nStartPos.length;i++) By51dk 7  
{ UtW"U0A  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c{]r{FAx9o  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 'y+bx?3Z  
nStartPos,nEndPos,i); p5twL  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x8SM,2ud  
fileSplitterFetch.start(); _Cv[`e.  
} vUo.BA#;.b  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v2Qc}o  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); a.Rp#}f  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,<^tsCI  
nEndPos = " + nFileLength); 4t%:O4 3e  
// fileSplitterFetch[nPos.length-1].start(); }<}`Q^Mlk  
3IJI5K_  
YaY;o^11/  
//等待子线程结束 !7Yt`l$$z  
//int count = 0; Ads<-.R  
//是否结束while循环 ^;Hi/KvM\  
boolean breakWhile = false; FkJ>]k  
!Z+*",]_  
xu_XX#9?b  
while(!bStop) U'h[ {ek  
{ ard3yNQt  
write_nPos(); 'n>3`1E,  
Utility.sleep(500); "dLMBY~  
breakWhile = true; lkSz7dr@  
,/w852|ub  
[F AOp@7W  
for(int i=0;i<nStartPos.length;i++) u]]5p[ |S  
{ [)J49  
if(!fileSplitterFetch.bDownOver) #g-*n@ 1  
{ L?D~~Jb  
breakWhile = false; cvs"WX3  
break; A&}nRP9  
} r 0?hX  
} {'c%#\  
if(breakWhile) WDH[kJ  
break; #8Id:56  
z!1/_]WJ,  
+EiUAs~H  
//count++; [:R P9r}  
//if(count>4) q~g&hR}K  
// siteStop(); FkxhEat8  
} TReM8Vd  
T^(n+lv  
u\1Wkxj  
System.err.println("文件下载结束!"); PGv}fEH"  
} d4/`:?w  
catch(Exception e){e.printStackTrace ();} KWigMh\r  
} zZ+LisSs&  
Q:fUM[  
YP\4XI  
//获得文件长度 Ng_rb KXC#  
public long getFileSize() \}4#**]  
{ %:be{Y6  
int nFileLength = -1; RZ/+ K=  
try{ ]=86[A-2N  
URL url = new URL(siteInfoBean.getSSiteURL()); UTK.tg  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ev;5 ?9\E  
httpConnection.setRequestProperty("User-Agent","NetFox"); "-j@GCme  
O%++0k;  
Pdo5 sve  
int responseCode=httpConnection.getResponseCode(); {HRxyAI!  
if(responseCode>=400) A^r [_dyZ  
{ *F8 uu.  
processErrorCode(responseCode); C!/8e (!N  
return -2; //-2 represent access is error ".Deu|>  
} ^?^|Y?f2P?  
dn)tP6qc/  
H:{(CY?t  
String sHeader; k+Ma_H`  
i:Z.;z$1  
QhE("}1  
for(int i=1;;i++) ]N(zom_0d  
{ Dpp52UnT E  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Ng;b!S  
//Utility.log(in.readLine()); d$?n6|4  
sHeader=httpConnection.getHeaderFieldKey(i); ,f /IG.  
if(sHeader!=null) _"w!KNX>(~  
{ ++{+ #s6  
if(sHeader.equals("Content-Length")) s<r.+zqW  
{ sm&rR=b  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); CO%O<_C  
break; &A5[C{x  
} Jn:GA@[I  
} 3d)+44G_)  
else {R{%Z  
break; _OxnHf:|  
} .&yWHdQC:  
} -_4jJxh=OB  
catch(IOException e){e.printStackTrace ();} jf)JPa_  
catch(Exception e){e.printStackTrace ();} $evuPm8G  
Y'a(J7  
O*n%2Mam  
Utility.log(nFileLength); @n;YF5  
1d@^,7MF-  
J>|:T  
return nFileLength; %k;FxUKi  
} yY g&'3  
 DIu72\  
gmAKW4(  
//保存下载信息(文件指针位置) 4#7@KhK}  
private void write_nPos() g`8 mh&u%  
{ dBq,O%$oq  
try{ h9n<ped`A;  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?L#SnnE  
output.writeInt(nStartPos.length); 1yRd10  
for(int i=0;i<nStartPos.length;i++) l;VGJMPi  
{ cV!/  
// output.writeLong(nPos); (_n8$3T75  
output.writeLong(fileSplitterFetch.nStartPos); l<K.!z<-:8  
output.writeLong(fileSplitterFetch.nEndPos); h }%M  
} "KT nX#<0  
output.close(); {FmFu$z+[  
} c%3 @J+z  
catch(IOException e){e.printStackTrace ();} 53&xTcv}x  
catch(Exception e){e.printStackTrace ();} zUgkY`]:BJ  
} G-i_s6Wu  
Xie dgy  
n_Hn k4  
//读取保存的下载信息(文件指针位置) ]aW.b_7<9  
private void read_nPos() w*ktx{  
{ &fy8,}  
try{ Joo)GIB  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .6/p4OR|  
int nCount = input.readInt(); |2&mvjk@H  
nStartPos = new long[nCount]; <@j  
nEndPos = new long[nCount]; Uus)2R7  
for(int i=0;i<nStartPos.length;i++) %Kfa|&'zV  
{ KeOBbe  
nStartPos = input.readLong(); K$vRk5U  
nEndPos = input.readLong(); n|,Vm@zV  
} MGC0^voe  
input.close(); ,Y5 4(>>%  
} #<>E+r+  
catch(IOException e){e.printStackTrace ();} zr9Pm6Rl  
catch(Exception e){e.printStackTrace ();} qlT:9*&g  
} fU~y481 A  
NGQIoKC  
]{U*+K%,J  
private void processErrorCode(int nErrorCode) l45F*v]^  
{ i&Cqw~.H  
System.err.println("Error Code : " + nErrorCode); \*"0wR;[K  
} 4sE=WPKF#  
F"#*8P  
O xaua  
//停止文件下载 4wD^?S!p  
public void siteStop() EGr5xR-  
{ k+G4<qw  
bStop = true; ZU@jtqq  
for(int i=0;i<nStartPos.length;i++) ~9;mZi1-  
fileSplitterFetch.splitterStop(); 8A]q!To  
;B7|tajd  
"lzg@=$|)  
} 5e8-?w% e  
} iw;Alav"x  
//负责部分文件的抓取 CrX-?$  
**FileSplitterFetch.java ?iO^b.'I#  
*/ (y4Eq*n%!  
package NetFox; cW/~4.v$  
g^^m a}i  
C4TD@  
import java.io.*; Ip\g ^ia  
import java.net.*; ]b=A/*z  
54_m{&hb  
*YOnX7*Km  
public class FileSplitterFetch extends Thread { 8-6{MJ?F  
vKLG9ovlY  
F qyJ*W\1  
String sURL; //File URL Ec/+9H6g  
long nStartPos; //File Snippet Start Position 'N/%SRk  
long nEndPos; //File Snippet End Position JkEQ@x  
int nThreadID; //Thread's ID -;.fU44O[#  
boolean bDownOver = false; //Downing is over }(O kl1  
boolean bStop = false; //Stop identical 1L9 <1  
FileAccessI fileAccessI = null; //File Access interface *4\ub:9  
#!j&L6  
sJYX[  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException jo:p*Q "F  
{ bbA<Zp  
this.sURL = sURL; j*\MUR=  
this.nStartPos = nStart; )p](*Z^  
this.nEndPos = nEnd; GDe$p;#"9g  
nThreadID = id; >%A=b}VS  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Y{{,62D  
} Du4?n8 o  
*Y>'v%  
fkG"72 95A  
public void run() L7="!I  
{ r2`?Ta  
while(nStartPos < nEndPos && !bStop) aq**w?l  
{ TK1M mL  
5Z0x2 jV  
F&Z>B};  
try{ N.J:Qn`(  
URL url = new URL(sURL); EE{%hGb  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); sA j$U^Gp  
httpConnection.setRequestProperty("User-Agent","NetFox"); 1x 8]&  
String sProperty = "bytes="+nStartPos+"-"; (VR nv  
httpConnection.setRequestProperty("RANGE",sProperty); a[#BlH  
Utility.log(sProperty); tjL#?j  
wQ95tN  
y!Eh /KD  
InputStream input = httpConnection.getInputStream(); bJvRQrj*3  
//logResponseHead(httpConnection); cZi&L p  
artS*fv3r  
@XJv9aq  
byte[] b = new byte[1024]; M QI=  
int nRead; VAz+J  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !1]xKNp ]  
{ eVJL|uI|  
nStartPos += fileAccessI.write(b,0,nRead); ";%1sK  
//if(nThreadID == 1) V6o,}o&-  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R'_[RHFC  
} RAa1KOxZX  
-#hl& ^u$  
d@~)Wlje  
Utility.log("Thread " + nThreadID + " is over!"); #-8/|_*  
bDownOver = true; zoXF"Nz  
//nPos = fileAccessI.write (b,0,nRead); 3?<vnpN=5d  
} ,s<d"]<  
catch(Exception e){e.printStackTrace ();} Yi,um-%  
} X13bi}O6#  
} ]z$<6+G  
+d. Bf  
06r cW `  
//打印回应的头信息 IrK )N  
public void logResponseHead(HttpURLConnection con) Z%{2/mQ  
{ '1IH^<b  
for(int i=1;;i++) i;7jJ(#V  
{ l$NEx0Dffz  
String header=con.getHeaderFieldKey(i); e;v2`2z2  
if(header!=null) {643Dz<e  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 'McVaPav  
Utility.log(header+" : "+con.getHeaderField(header)); T!AQJ:;1  
else A#{*A  
break; o! N@W  
} *0tNun 5=3  
} r>OE[C69  
9)`wd&!  
_;+&'=6.[  
public void splitterStop() :I8t}Wg  
{ 1,,:4 *)  
bStop = true; 37DvI&  
} SJmri]4K  
23m+"4t  
Obm\h*$  
} :>u{BG;=79  
TW$^]u~v  
G{9y`;  
/* {0~ p"%*  
**FileAccess.java e78}  
*//文件访问(定位,写) 6I<`N  
package NetFox; ^  +G> N  
import java.io.*; ud1E@4;qf  
?6gI8K6X  
[DviN  
public class FileAccessI implements Serializable{ mE1*F'0a  
xMu6PM<l  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -`JY] H  
RandomAccessFile oSavedFile; N_U D7P1  
long nPos; nDfDpP&  
?M);wBe(  
-b<+Ra  
public FileAccessI() throws IOException 1{qg@xlj  
{ Y2fs$emv  
this("",0); A}o1I1+  
} \hVFK6  
r0,}f\  
F$v G=3  
public FileAccessI(String sName,long nPos) throws IOException |b'AWI81D  
{ w67Pw  
oSavedFile = new RandomAccessFile(sName,"rw"); H}/1/5 L  
this.nPos = nPos; }OZfsYPz}T  
oSavedFile.seek(nPos); d p].FS  
} qp8;=Nfa  
+a{>jzR  
P^z)]K#sw  
public synchronized int write(byte[] b,int nStart,int nLen) 4-AmzU  
{ Qoc-ZC"<6  
int n = -1; i@6 kI C  
try{ uQ}kq7gd  
oSavedFile.write(b,nStart,nLen); !{+(oDN  
n = nLen; &^"m6  
} Y\\&~g42R2  
catch(IOException e) DBRTZES  
{ ,k4 (b  
e.printStackTrace (); BC3I{Y |  
} d*(1t\  
00ho*p!E'  
@W8RAS~  
return n; YI/vt2  
} 8GX@76o  
>8c9-dTmf  
4f+Ke*^[RA  
} xE:p)B-]  
:v+ 39  
o_S8fHqjt  
/* `%VrT`  
**SiteInfoBean.java 6mZFsB  
*/ .nnAI@7E  
package NetFox; _nF_RpS  
JL1Whf  
M~v{\!S  
public class SiteInfoBean { d] {^  
X#fI$9a  
Cs<d\"+  
private String sSiteURL; //Site's URL $K hc?v  
private String sFilePath; //Saved File's Path o Vs&r?\Z  
private String sFileName; //Saved File's Name `R\0g\  
private int nSplitter; //Count of Splited Downloading File :?zOLw?(  
1*s Lj#  
@d)6LA9Ec  
public SiteInfoBean() q;U[f6JjE  
{//nSplitter的缺省值为5 aV1(DZ83  
//default value of nSplitter is 5 MQ01!Y[q_7  
this("","","",5); 4GJsVA(d|  
}   ~*RNJ  
h c "n?  
3OTSLF/  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #'8E%4  
{ 6<2 7}S  
sSiteURL= sURL; <7qM;) g  
sFilePath = sPath; $8b/"Qm  
sFileName = sName; k;]&`c^5  
this.nSplitter = nSpiltter; 0 @>3fR  
9d v+u6)  
"&An9H'  
} $WDa} ~j~^  
B<W{kEY  
2`x[y?Tn  
public String getSSiteURL() 3a =KgOvp  
{ ^z_~e@U  
return sSiteURL; FQ_4a}UOjX  
} ke/QFN-`  
9G&l{7=  
<)&;9C  
public void setSSiteURL(String value) 3K{'~?mM  
{ Bb m1&d#  
sSiteURL = value; >n#Pq{7aF  
} .Sm7na K  
i=Y#kL~f  
0-7xcF@s  
public String getSFilePath() #P1k5!u  
{ B>Mk "WjQ  
return sFilePath; =OCHV+m  
} +Oo>V~  
{'JoVJKv  
v~j21`  
public void setSFilePath(String value) |]V0sgpoZ  
{ \S _ycn  
sFilePath = value; (@]{=q<  
} ~G"5!,J  
!pgkUzMW  
|iU#!+zY  
public String getSFileName() `Q,03W#GJ%  
{ xGN&RjPk\  
return sFileName; X ZfT;!wF&  
} zUWu5JI  
8|gwH2 st~  
@hp@*$#& 9  
public void setSFileName(String value) E` BL3+kQ  
{ ka655O/)&  
sFileName = value; #49,7OBU  
} JpN+'/  
4~DoqT  
N|wI=To  
public int getNSplitter() @xR=bWY  
{ 074)(X&:x  
return nSplitter; kLK}N>v}X  
} VXQ~PF]z0  
W2s6!_AN  
Ft'?43J  
public void setNSplitter(int nCount) Y'wQ(6ok  
{ yi PMJ  
nSplitter = nCount; THC34u]  
} R0vWj9nPh  
} B\`4TU}kE  
4vF1  
wP29 xV"5  
/* y\]:&)?&C^  
**Utility.java ,iV|^]X3$/  
*/ _O{3bIay3!  
package NetFox; Z)?B5FF  
>yiK&LW^?  
:T.j;~  
public class Utility { e2~&I`ct  
N2WQrTA:S+  
"6o}g.  
public Utility() U,\3 !D0jt  
{  Q#i[Y?$L  
DHQavHqbZ  
ly9.2<oz}L  
} >La!O~d  
1?\G6T  
//线程睡眠 yP. ,Dh s  
public static void sleep(int nSecond) !/2u O5  
{ d?)k<!fJk  
try{ _XvSe]`f`  
Thread.sleep(nSecond); 5=(fuY3  
} Y {a#2(xn  
catch(Exception e) u[k0z!p_ c  
{ yL{X}:;}  
e.printStackTrace (); (hr*.NS#  
} Fu].%`*xJ  
} ):-\TVz~  
06X4mu{  
//日志 R <}UT  
public static void log(String sMsg) A%(t'z  
{ &?59{B. mD  
System.err.println(sMsg); :(ni/,~Q  
} TL'^@Y7X5  
g$+ $@~  
j6}/pe*;;T  
public static void log(int sMsg) O!xul$9  
{ N;gI %6  
System.err.println(sMsg); }&!fT\4  
} @'P\c   
} /r2*le (H  
d|I?%LX0p  
kzozjh%`9h  
/* iW oe  
**TestMethod.java |T3F:],`  
*/ m%7T ~  
package NetFox; I8M^]+c  
7 G37V"''  
20h+^R3{Z  
public class TestMethod { II;   
<l>o6K  
?9W2wqN>o  
public TestMethod() J7a_a>Y  
{ ///xx/weblogic60b2_win.exe mQwP-s  
try{ LlbRr.wL  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4}&$s  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); D6z*J?3^#&  
SiteFileFetch fileFetch = new SiteFileFetch(bean); $1KvL8  
fileFetch.start(); cug=k  
} P~xP@? I%  
catch(Exception e){e.printStackTrace ();} _e4%<!1  
xWR<>Og.  
A-S!Z2m\  
}  a>6@1liT  
mLGbwm'K  
S1SsJo2\  
public static void main(String[] args) | 6/ # H*  
{ }:SWgPfc  
new TestMethod(); (58}G2}q  
} $<DcbJW  
} m6wrG`-di  
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