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http断点续传简单实现(java)

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/* XGE:ZVpW  
**SiteFileFetch.java BXgAohg!  
*/ =|IB=  
package NetFox; h?wNmLre  
import java.io.*; y=y=W5#;77  
import java.net.*; FoM4QO  
{~DYf*RZ  
xao'L  
public class SiteFileFetch extends Thread { \-k X-Tq  
2kV[A92s  
aaq{9Y#  
SiteInfoBean siteInfoBean = null; //文件信息Bean '| Enc"U  
long[] nStartPos; //开始位置 c)8V^7=Q  
long[] nEndPos; //结束位置 &0*l=!:G^  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 3ThCY`  
long nFileLength; //文件长度 7 }`c:u~j  
boolean bFirst = true; //是否第一次取文件 loVUB'OSv  
boolean bStop = false; //停止标志 [Af&K22M(X  
File tmpFile; //文件下载的临时信息 a p-\R  
DataOutputStream output; //输出到文件的输出流 $"[1yQ<p  
P+pL2BA  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) O[Xl*9P  
public SiteFileFetch(SiteInfoBean bean) throws IOException X%W_cb2  
{ j`I[M6Qxh  
siteInfoBean = bean; LjUBV_J  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 5Cxh >,k  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); "Y@rNmBj  
if(tmpFile.exists ()) &Im{p7gf!b  
{ kR%bdN  
bFirst = false; =T5vu~[J/e  
read_nPos(); xz#;F ,`ZR  
} Zd@'s.,J  
else LO@.aJpp  
{ xq_%|p}y  
nStartPos = new long[bean.getNSplitter()]; Q g=k@  
nEndPos = new long[bean.getNSplitter()]; z'a#lA.$}  
} G)\s{qk  
c;_GZ}8  
?(GMe>  
WTPp/Nq'  
} GSg|Gz""J0  
/0QGU4=  
dw,Nlf~*0  
public void run() <>GWSW  
{ Q\G8R^9j p  
//获得文件长度 f!;i$Oif  
//分割文件 BQWEC,*N  
//实例FileSplitterFetch !}wJ+R ^2  
//启动FileSplitterFetch线程 0S@O]k)  
//等待子线程返回 d;&'uiS  
try{ g~_cYy  
if(bFirst) evf){XhT;n  
{ Kx9Cx 5B  
nFileLength = getFileSize(); ty]JUvR@  
if(nFileLength == -1) ]bO {001y,  
{ bHcb+TR3  
System.err.println("File Length is not known!"); b u%p,u!  
} QC0^G,9.  
else if(nFileLength == -2) T[M?:~  
{ nt\6o?W  
System.err.println("File is not access!"); "~x\bSY  
} ]c{Zh?0  
else _3<J!$]&p  
{ lbrob' '+  
for(int i=0;i<nStartPos.length;i++) :@w ;no>=*  
{ 21GjRPs\  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ,c"_X8Fkx$  
} QytqO {B^  
for(int i=0;i<nEndPos.length-1;i++) 2%0z PflT  
{ x8%Q TTY  
nEndPos = nStartPos[i+1]; }xTTz,Oj$  
} |33pf7o  
nEndPos[nEndPos.length-1] = nFileLength; j>~^jz:  
} uy\< t  
} T/G1v;]  
P\;lH"9  
B&A4-w v  
//启动子线程 [dFxW6n  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; XOzPi*V**  
for(int i=0;i<nStartPos.length;i++) P8!Vcy938  
{ CYrVP%xRA  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r AMnM>`  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), jPYed@[+  
nStartPos,nEndPos,i); zR h1  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fV*x2g7w  
fileSplitterFetch.start(); Ous[{"-J  
} W >eJGZ<  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W"4E0!r  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {EbR =  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", STu!v5XY}-  
nEndPos = " + nFileLength); g[Ah> 5  
// fileSplitterFetch[nPos.length-1].start(); 'qQ 5K o  
 fI[tU(x  
YIb5jK `  
//等待子线程结束 *%(8z~(\  
//int count = 0; v=nq P{  
//是否结束while循环 ,GXwi|Y  
boolean breakWhile = false; &H,5f#  
q a#Fa)g*  
@B5@3zYs  
while(!bStop) [P8Y  
{ OQaM47"  
write_nPos(); c#nFm&}dm  
Utility.sleep(500); .:Bjs*  
breakWhile = true; wl2rw93  
6~?7CK  
/S1EQ%_  
for(int i=0;i<nStartPos.length;i++) CyO2Z  
{ p%,:U8fOR  
if(!fileSplitterFetch.bDownOver) 3;~1rw=$<  
{ o%X_V!B{V  
breakWhile = false; `x$d8(1J`#  
break; >x@]w sj  
} X!&DKE  
} %1SA!1>j  
if(breakWhile) aq~hl7MTj  
break; 8#'<SB  
hXM8`iFW5  
~\4l*$3(^  
//count++; )v;>6(  
//if(count>4) AuUT 'E@E  
// siteStop(); w_pEup\`  
} m9ts&b+TE  
F6h3M~uR  
*c7kB}/  
System.err.println("文件下载结束!"); %]nY v#K  
} @=`Dw/13  
catch(Exception e){e.printStackTrace ();} ,0NVb7F;k  
} z*ZEw  
2\l7=9 ]\3  
Z"'rc.>a  
//获得文件长度 jVL<7@_*  
public long getFileSize() ^"v~hjM#  
{ UevbLt1Y  
int nFileLength = -1; J|_&3@r  
try{ ^M6v;8EU  
URL url = new URL(siteInfoBean.getSSiteURL()); im9 B=D  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /XS6X  
httpConnection.setRequestProperty("User-Agent","NetFox"); '?t]iRCeI7  
[J\5DctX;c  
9_ JK.  
int responseCode=httpConnection.getResponseCode(); :Gqyj_|<  
if(responseCode>=400) 9=@j]g|  
{ >T;"bc b  
processErrorCode(responseCode); ]Gow  
return -2; //-2 represent access is error *$/7;CLq  
} yw"FI!M  
j]rE0Og  
>4}+\ Q`S  
String sHeader; h'^7xDw  
2/=CrK  
6:>4}WOP  
for(int i=1;;i++) ??=CAU%\  
{ /ivt8Uiw  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]0by6hQ  
//Utility.log(in.readLine()); cf1Ve\(YGI  
sHeader=httpConnection.getHeaderFieldKey(i); 'Kxs>/y3  
if(sHeader!=null) -en:81a#  
{ }|H]>U&  
if(sHeader.equals("Content-Length")) (`GO@  
{ "6^tG[G%  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,& =(DJ  
break; tf|/_Y2  
} #!rng]p  
} iHr{ VQ  
else VF!?B>  
break; |!8[Vg^Wh  
} jC ,foqL  
} f3lFpS  
catch(IOException e){e.printStackTrace ();} <i^Bq=E<rJ  
catch(Exception e){e.printStackTrace ();} N\=pH{  
?'CIt5n+\{  
pA"x4\s   
Utility.log(nFileLength); ()JM161  
1lfkb1BM  
k6ER GQ9|I  
return nFileLength; f% ZqK_CW  
} [0yKd?e  
?(Dkh${@  
9 H2^4D8  
//保存下载信息(文件指针位置) K6@QZc5.!  
private void write_nPos() =#^%; 66z  
{ D^=_408\  
try{ L{bcmo\U  
output = new DataOutputStream(new FileOutputStream(tmpFile)); go m< V?$  
output.writeInt(nStartPos.length); c?CwxI_b8  
for(int i=0;i<nStartPos.length;i++) gZ   
{ x%B^hH;W  
// output.writeLong(nPos); @Rj&9/\L  
output.writeLong(fileSplitterFetch.nStartPos); =DvFY]9{  
output.writeLong(fileSplitterFetch.nEndPos); dl'pl  
} Me yQ`%  
output.close(); vi4u `  
} 6/hY[a!  
catch(IOException e){e.printStackTrace ();} i&-g 0  
catch(Exception e){e.printStackTrace ();} n*CH,fih:  
} {#: js  
upQ:C>S  
PH9MB  
//读取保存的下载信息(文件指针位置) qCSJ=T;  
private void read_nPos() =`xk|86f  
{ iN0pYqY*  
try{ ?}m/Q"!1  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <?&GBCe  
int nCount = input.readInt(); Tc,Bv7:  
nStartPos = new long[nCount]; ;i^p6b j  
nEndPos = new long[nCount]; UAnq|NJO  
for(int i=0;i<nStartPos.length;i++) jiYYDGs77  
{ h/5n+*x(  
nStartPos = input.readLong(); Fo3[KW)8I  
nEndPos = input.readLong(); 8;P8CKe  
} 'M|W nR  
input.close(); \2U^y4K.  
} S h=E.!  
catch(IOException e){e.printStackTrace ();} <>A:Oi3^  
catch(Exception e){e.printStackTrace ();} a k@0M[d  
} @j`_)Y\  
g[@Kd  
2JYp.CJv  
private void processErrorCode(int nErrorCode) gTY\B.  
{ mwZesSxB_  
System.err.println("Error Code : " + nErrorCode); yrnB]$hf  
} pAtHU(}  
 8;4vr@EV  
Pqo _ +fL+  
//停止文件下载 S+R<wv ,6  
public void siteStop() >"f,'S5*  
{ BXO(B'1)]  
bStop = true; VE& ?Zd~  
for(int i=0;i<nStartPos.length;i++) Oq(_I b)9  
fileSplitterFetch.splitterStop(); /4YXx|V  
PYkcGtVa_  
k[6@\D-  
} }el. qZ  
} e7t).s)b{  
//负责部分文件的抓取 +[UFf3(ON  
**FileSplitterFetch.java wA+J49  
*/ ^uW](2  
package NetFox; _ YWw7q  
yX,2`&c  
l\- 1W2  
import java.io.*; HLg/=VF7?  
import java.net.*; 1Z'cL~9  
9hHQWv7TgK  
FviLlly6  
public class FileSplitterFetch extends Thread { -TU7GCb=  
}IC$Du#  
r[vMiVb  
String sURL; //File URL A-~#ydv  
long nStartPos; //File Snippet Start Position : &mYz(1q  
long nEndPos; //File Snippet End Position iJ~5A'?6  
int nThreadID; //Thread's ID [3nhf<O  
boolean bDownOver = false; //Downing is over S5@/;T  
boolean bStop = false; //Stop identical fa=#S  
FileAccessI fileAccessI = null; //File Access interface SDcxro|8i  
p.n]y=o.)  
F:%= u =  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException j2cLb  
{ K7F uMB  
this.sURL = sURL; },2-\-1  
this.nStartPos = nStart; DIB Az s  
this.nEndPos = nEnd; W8,XSUl  
nThreadID = id; hmtRs]7  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @/lLL GrZ"  
} W,`u5gbT  
f~jx2?W  
u6'vzLmM  
public void run() #^gn,^QQ  
{ {:IOTy  
while(nStartPos < nEndPos && !bStop) l,1}1{k&  
{ 9r fR  
j?jEWreq]~  
?g}n$%*5y!  
try{ >MUwT$szs  
URL url = new URL(sURL); : :uD%a zd  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /R8>f  
httpConnection.setRequestProperty("User-Agent","NetFox"); XLwbA4ORq  
String sProperty = "bytes="+nStartPos+"-"; ];R5[%:5  
httpConnection.setRequestProperty("RANGE",sProperty); u'd+:uH  
Utility.log(sProperty); f62z9)`^  
W:aAe%S  
LbJ tU !  
InputStream input = httpConnection.getInputStream(); ~q?IG5s*Z  
//logResponseHead(httpConnection); 0Tp?ED_  
-3/:Dk`3  
_c['_HC  
byte[] b = new byte[1024]; }zj w\  
int nRead; r6Lb0PzMf  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Q`7!~qV0=  
{ '/\@Mc4T  
nStartPos += fileAccessI.write(b,0,nRead); FZ #ngrT  
//if(nThreadID == 1) WVftLIJ  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r[eZV"  
} k*-_CO-h  
D=mU!rjr1  
Lbq"( b  
Utility.log("Thread " + nThreadID + " is over!"); _0)#-L>xKF  
bDownOver = true; X9/V;!  
//nPos = fileAccessI.write (b,0,nRead); C(3yJzg>y  
} i`gsT[JQRX  
catch(Exception e){e.printStackTrace ();} P~#!-9?  
} \_!FOUPz(  
} E(4ti]'4  
S&6}9r  
.hg<\-:_  
//打印回应的头信息 H #J"'  
public void logResponseHead(HttpURLConnection con) :u'X ~ID[  
{ DGC -`z  
for(int i=1;;i++) ;QR|v  
{ prlnK  
String header=con.getHeaderFieldKey(i); 5u:+hB  
if(header!=null) r4gkSwy  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5dMIv<#T`  
Utility.log(header+" : "+con.getHeaderField(header)); %Wom]/&,'  
else s2@N&7"u)  
break; w(J-[t118  
} @!Il!+^3  
} [{Fr{La`D'  
$.QnM  
H+F?)VX}oA  
public void splitterStop() T5z %X:VD(  
{ Bt Bo%t&  
bStop = true; "ltvD\  
} 8q)2 )p  
`-\4Dx1!q  
Z%`} `(  
} 7Fq mT  
9u1_L`+b  
CHdw>/5  
/* N Rcg~Nu  
**FileAccess.java mZ/?uPIa  
*//文件访问(定位,写) (*/P~$xIj  
package NetFox; s$C;31k  
import java.io.*; 9$~D4T  
{Xwin $C  
z Rz#0  
public class FileAccessI implements Serializable{ 8!3+Obj  
@IB8(TZ5I  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "3Dvc7V  
RandomAccessFile oSavedFile; VDPqI+z  
long nPos; %saTyF,  
Fy`VQ\%7t  
).9-=P HlX  
public FileAccessI() throws IOException ;)83tx /  
{ 3Nr8H.u&q  
this("",0); k|BY 7C  
} Xvi{A]V  
56>Zqtp*  
, $}P<WZMu  
public FileAccessI(String sName,long nPos) throws IOException sG}}a}U1  
{ %a5Sc|&-  
oSavedFile = new RandomAccessFile(sName,"rw"); G2;Uv/vR  
this.nPos = nPos; *B#OLx  
oSavedFile.seek(nPos); U^VFHIm  
} uji])e MN~  
To}L%)  
5iG|C ~  
public synchronized int write(byte[] b,int nStart,int nLen) k/H<UW?Z]  
{ 1ikkm7  
int n = -1; ^[&*B#(  
try{ 6du"^g  
oSavedFile.write(b,nStart,nLen); s_zZ@azJ  
n = nLen; Y91TF'  
} xtpD/,2  
catch(IOException e) j[iJo 5  
{ p&Nw:S  
e.printStackTrace (); Kl(}s{YFn.  
} ]K XknEaxl  
0 v/+%%4}  
JR 2v}b  
return n; A |NX"  
} OTN"XKa$  
U=Z@Ipu5T  
'! yyg#  
} b2U[W#  
`"GD'Oa  
(cC5zv*E  
/* nqgfAQsE)  
**SiteInfoBean.java w V;y]'  
*/ #xYkG5`lm  
package NetFox; BzTm[`(h  
$T;3*D90  
YyK9UZjI  
public class SiteInfoBean { aFIet55o  
#g~~zwx/N  
@{+*ea7M(`  
private String sSiteURL; //Site's URL u>k;P UH4  
private String sFilePath; //Saved File's Path &_q;X;}  
private String sFileName; //Saved File's Name um&N|5lHb  
private int nSplitter; //Count of Splited Downloading File 5mER&SX  
Rv.W~FE^  
(ter+rTv  
public SiteInfoBean() O- |RPW}  
{//nSplitter的缺省值为5 CdWGb[uI  
//default value of nSplitter is 5 qaw5<  
this("","","",5); G?3S_3J2  
} OX8jCW  
Q{>9Dg  
p&vQ* }  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) y,Dfqt  
{ N#T MU  
sSiteURL= sURL; XKks j!'B  
sFilePath = sPath; `+"QhQ4 w  
sFileName = sName; KO{}+~,.6  
this.nSplitter = nSpiltter; Kz$Ijj  
~\ie/}zYj  
ip1jY!   
} bpUN8BI[T  
;pAkdX&b  
^$?8!WE  
public String getSSiteURL() _QXo4z!a8  
{ QXXcJc~  
return sSiteURL; c^Wm~"r  
} FAPgXmFzx  
@ o;m!CYB  
>x!N@G  
public void setSSiteURL(String value) (&njZdcb*  
{ 61jDI^:  
sSiteURL = value; 6|_ S|N  
} V#3VRh  
;`F0 %0d  
R L)'m  
public String getSFilePath() ?$ YE  
{ qIb(uF@l"  
return sFilePath; laFkOQI  
} ?#FA a,  
hrS/3c'<Z  
~x4Y57  
public void setSFilePath(String value) jg%D G2  
{ XZKOBq B]  
sFilePath = value; ghms-.:b8  
} <<UlFE9"  
k{@z87+&  
Ch7eUTq A@  
public String getSFileName() AiO,zjM=  
{ f kP WGd  
return sFileName; ~_S`zzcZy4  
} [FC%_R&&  
YI\^hP#  
-p%=36n  
public void setSFileName(String value) &TK%igL  
{ 1 ViDS  
sFileName = value; YVs{\1|'  
}  1XHGW=n  
9oGsrC lH  
L G=Q  
public int getNSplitter() rNgE/=X  
{ FEdyh?$  
return nSplitter; c)E'',-J_2  
} -Tz9J4xU&  
ja 9y  
E )Hp.  
public void setNSplitter(int nCount) wHIS}OONz  
{ u$a%{46  
nSplitter = nCount; 'i`;Frmg  
} y<;#*wB  
} {ifYr(|p`  
l@Ml8+  
hob%'Y5%D  
/* V}aXS;(r%  
**Utility.java wz:wR+  
*/ JH?[hb  
package NetFox; d}WAP m  
re^1fv  
0} {QQB  
public class Utility { .@[+05Yw  
qbT].,?!U  
$(_i>&d<  
public Utility() c\RDa|B,  
{ v$,9l+p/  
_N*4 3O`  
(# ?~^ut  
} sS+9ly{9J  
]INbRytvc  
//线程睡眠 )IhI~,0Nmj  
public static void sleep(int nSecond) Y@L`XNl  
{ HPt"  
try{ T> 1E  
Thread.sleep(nSecond); Yoaz|7LS  
} KH[%HN5v  
catch(Exception e) { >4exyu6  
{ $/pd[H[{  
e.printStackTrace (); lYJ]W[!  
} Y> 7/>x6  
} <M 7WWtmx  
|'a5n h!  
//日志 %tpt+N?  
public static void log(String sMsg) O(!wDnhc  
{ rb,&i1  
System.err.println(sMsg); *8MU,6  
} b$M? _<G  
]Oe#S"-Oo  
B)Gm"bLCOZ  
public static void log(int sMsg) XmXHs4  
{ y]@_DL#J=  
System.err.println(sMsg); 9]d$G$Kv9  
} Kk#8r+ ,  
} BWQ (>Z"  
*t*yozN  
1?mQ fW@G  
/* !".@Wg$  
**TestMethod.java T}fo:aB}  
*/ U?@UIhtM|  
package NetFox; qwVpGNc45  
;O.U-s  
)vo PH)!  
public class TestMethod { O5e9vQH  
Gn&)*qCO  
<0Q`:'\.>  
public TestMethod() UT>\u  
{ ///xx/weblogic60b2_win.exe  \ 1|T  
try{ &@{ Ba~S  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =f{r+'[;^  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 44b'40  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6rPe\'n=B  
fileFetch.start(); /FB'  
} w~1K93/p!  
catch(Exception e){e.printStackTrace ();} LN_6>u  
dD!} P$  
|\elM[G"g  
} wUl}x)xo  
9jJ&QACn  
DJ=miJI'  
public static void main(String[] args) HO$s&}t  
{ 191O(H  
new TestMethod(); 3hb1^HNT  
} k>2 xm  
} w^P4_Yr  
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