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http断点续传简单实现(java)

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/* {>hC~L?6  
**SiteFileFetch.java ~?d Nd  
*/ j+$rj  
package NetFox; wl#@lOv-P  
import java.io.*; (|klSz_4LM  
import java.net.*; 9\_eK,*B  
8%A#`)fb  
'>-gi}z7  
public class SiteFileFetch extends Thread { m qMHL2~  
(nf~x  
Z2qW\E^_r  
SiteInfoBean siteInfoBean = null; //文件信息Bean /5(Yy}  
long[] nStartPos; //开始位置 %A1o.{H  
long[] nEndPos; //结束位置 TO]@ Zu1  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ~*z% e*EL  
long nFileLength; //文件长度 gOSJM1Mr3  
boolean bFirst = true; //是否第一次取文件 ME46V6[LX]  
boolean bStop = false; //停止标志 =P't(<  
File tmpFile; //文件下载的临时信息  zv0l,-o  
DataOutputStream output; //输出到文件的输出流 a&/#X9/  
TaKLzd2  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) d3 ZdB4L  
public SiteFileFetch(SiteInfoBean bean) throws IOException 1w@(5 ^V  
{ TN+iA~kQ  
siteInfoBean = bean; % 5M/s'O?i  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); kMi/>gpQ  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); e2s]{obf  
if(tmpFile.exists ()) HK,cJah q  
{ }wr{W:j  
bFirst = false; X' H[7 ^W  
read_nPos(); RJ  8+h  
} gQWa24  
else hYPl&^  
{ I*{4rDt  
nStartPos = new long[bean.getNSplitter()]; ,':fu  
nEndPos = new long[bean.getNSplitter()];  P5a4ze  
} xS4w5i2  
8m2Tk\;:  
n.!#P|  
ZSjMH .Ij"  
} #@YPic"n7`  
.}t~'*D  
]O+Ma}dxz:  
public void run() {o_X`rgrL  
{ _=_Px@<Q  
//获得文件长度 ,k )w6)  
//分割文件 1+szG1U=  
//实例FileSplitterFetch = RA /  
//启动FileSplitterFetch线程 DS+}UO  
//等待子线程返回 :ubV};  
try{ 4>F'oqFF  
if(bFirst) dP# |$1  
{ ub^h&= \S  
nFileLength = getFileSize(); #hfXZVD  
if(nFileLength == -1) \KMToN&2  
{ tItX y  
System.err.println("File Length is not known!"); [I '0,y  
} }zkHJxZgE  
else if(nFileLength == -2) _<k\FU r  
{ I4/8 _)b^  
System.err.println("File is not access!"); IHam4$~-  
} '&x#rjo#  
else z>58dA@f  
{ N60rgSzI  
for(int i=0;i<nStartPos.length;i++) _4"mAPt  
{ }Lc-7[/  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); R.jIl@p   
} sF!($k;!  
for(int i=0;i<nEndPos.length-1;i++) G_;)a]v8)  
{ Sj]T   
nEndPos = nStartPos[i+1]; GPkmf%FJ  
} 2D75:@JL}|  
nEndPos[nEndPos.length-1] = nFileLength; qkt0**\  
} QLXN*c  
} m+`fn;*  
w~(1%p/  
.L9j>iP9 *  
//启动子线程 mg^I=kpk  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~zHjMo2  
for(int i=0;i<nStartPos.length;i++) S^-DK~Xt4  
{ 0Vlk;fIh  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(),  aC$B2  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), aZ2!i  
nStartPos,nEndPos,i); ]NUl9t*N4  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); JlH&??  
fileSplitterFetch.start(); K(q+ "  
} ]$ L|  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'n{Nvt.c  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +c(zo4nZ  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^T*?>%`  
nEndPos = " + nFileLength); ![`Ay4AZ@a  
// fileSplitterFetch[nPos.length-1].start(); u[@l~gwL  
Eo{"9j\  
3.|S  
//等待子线程结束 F~T]u2qt  
//int count = 0; }Mstjm  
//是否结束while循环 S{]x  
boolean breakWhile = false; SX<` {x&L  
iP =V8g?L  
+MR.>"  
while(!bStop) 8$")%_1]  
{ *,e:]!*  
write_nPos(); ]JCvyz H  
Utility.sleep(500); -=%@L&y1  
breakWhile = true; QqFR\6  
(\\eo  
XRcqhv  
for(int i=0;i<nStartPos.length;i++) {_7 i8c<s=  
{ o C<.=2]  
if(!fileSplitterFetch.bDownOver) g<l1zo`_  
{ JSkLEa~<  
breakWhile = false; S)cLW~=z  
break; I9/W;# *~  
} J2::'Hw*s  
} v4u5yy_;(  
if(breakWhile) NG--6\  
break; 2;z b\d  
hlV=qfc  
igkYX!0#8O  
//count++; 1Yq?X:  
//if(count>4) Gr7=:+0n|P  
// siteStop(); tX5"UQA  
} g l^<Q  
cv?06x{  
q1z"-~i )E  
System.err.println("文件下载结束!"); n!NS(. o  
} tXoWwQD;Y  
catch(Exception e){e.printStackTrace ();} k[bD\'  
} @JtM5qB  
JW{rA6?   
q)Lu_6 mg  
//获得文件长度 3Ndq>  
public long getFileSize()  8cU}I4|  
{ y+X2Pl  
int nFileLength = -1; M.x=<:upp  
try{ [0(B>a3J  
URL url = new URL(siteInfoBean.getSSiteURL()); N/Z2hn/m  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); % W=b? :  
httpConnection.setRequestProperty("User-Agent","NetFox"); `);AW(Q  
Xnz3p"  
GNgKo]u  
int responseCode=httpConnection.getResponseCode(); W ?qmp|YD  
if(responseCode>=400) 4.Q} 1%ZN  
{ a2dnbfSWa[  
processErrorCode(responseCode); OjFLPGRCh  
return -2; //-2 represent access is error =8t]\Y?  
} &:/hrighH  
T V<'8 L  
=7w\ 7-.m  
String sHeader; 9Xj7~,  
_kj wFq  
ur3(HL  
for(int i=1;;i++) S4'   
{ T;L>;E>B  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !zkZQ2{Wn  
//Utility.log(in.readLine()); u -;_y='m  
sHeader=httpConnection.getHeaderFieldKey(i); d*jMZ%@uS  
if(sHeader!=null) wj,:"ESb4  
{ 87BHq)  
if(sHeader.equals("Content-Length")) tZ'|DCT  
{ 6{"$nF]  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); v:!Z=I}>  
break; |_] Q$q[[%  
} ePr&!Tz#  
} 2^y ^q2(r  
else <}E!w_yi  
break; pnjXf.g"O  
} 4(|cG7>9-  
} ba[1wFmcL  
catch(IOException e){e.printStackTrace ();} qHuZcht  
catch(Exception e){e.printStackTrace ();} v-#Q7T  
#pb92kA'  
e4!:c^?  
Utility.log(nFileLength); X'd9[).  
)\eI;8  
%+j8["VEC  
return nFileLength; LW[9  
} m;'6MHx;  
()5[x.xK@  
X;i~ <Tq  
//保存下载信息(文件指针位置) EH256f(&  
private void write_nPos() gu0j.XS^  
{ TM_/ `a2}  
try{ >+JqA7K  
output = new DataOutputStream(new FileOutputStream(tmpFile)); v3aYc:C  
output.writeInt(nStartPos.length); }q $5ig  
for(int i=0;i<nStartPos.length;i++) y0#u9t"Z;  
{ oXb;w@:  
// output.writeLong(nPos); N>XS=2tzN  
output.writeLong(fileSplitterFetch.nStartPos); $}) g?Q  
output.writeLong(fileSplitterFetch.nEndPos); P!H_1RwXKC  
} *1v[kWa?  
output.close(); Y"~gw~7OD  
} ^lA=* jY(  
catch(IOException e){e.printStackTrace ();} ~F4fFQ-yy  
catch(Exception e){e.printStackTrace ();} E~]R2!9  
} qAn!RkA  
pi Z[Y 5OE  
OW3sS+y  
//读取保存的下载信息(文件指针位置) w2 a1mU/  
private void read_nPos() >4#)r8;dx  
{ Y0x%sz 5  
try{ 5Ow[~p"l<  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `8AR_7i  
int nCount = input.readInt(); hp#W 9@NR  
nStartPos = new long[nCount]; %k;|\%B`  
nEndPos = new long[nCount]; (Tn- >).AO  
for(int i=0;i<nStartPos.length;i++) 0w)^)  
{ l:j4Ft 8  
nStartPos = input.readLong(); |N%fMPKa  
nEndPos = input.readLong(); hWD;jR  
} IFF92VD&  
input.close(); Hea;?4Vg  
} g/P+ZXJ  
catch(IOException e){e.printStackTrace ();} -(  
catch(Exception e){e.printStackTrace ();} bYEy<7)x  
} ,1[q^-9  
'}fzX2Q#  
NYrQ$N"  
private void processErrorCode(int nErrorCode) v6>_ j L  
{ {ys=Ndo8  
System.err.println("Error Code : " + nErrorCode); {u#;?u=|  
} =<?+#-;p  
-Z 4e.ay5  
/ c AUl  
//停止文件下载 DNr@u/>vB  
public void siteStop() M luVx'  
{ GBRa.;Kk  
bStop = true; /atW8 `&  
for(int i=0;i<nStartPos.length;i++) Q36qIq_0e  
fileSplitterFetch.splitterStop(); V:VO[e<e  
~GL] wF2#  
G LIi6  
} aqj@Cjk4Z  
} ,.OERw  
//负责部分文件的抓取 (NF~Ck$#q  
**FileSplitterFetch.java @GdbTd  
*/ ";3zX k[#  
package NetFox; vUohtS*  
3Nq N \5B:  
dwDcR,z?a  
import java.io.*; u*Pibgd<  
import java.net.*; P_*" dza  
_V7r1fY:  
X!9 B2w  
public class FileSplitterFetch extends Thread { #,":vr  
*7ZN]/VRT  
>zXsNeGQR  
String sURL; //File URL &6ZD136  
long nStartPos; //File Snippet Start Position e[&L9U6GW-  
long nEndPos; //File Snippet End Position KG|n  
int nThreadID; //Thread's ID LR".pH13  
boolean bDownOver = false; //Downing is over nV-mPyfL8  
boolean bStop = false; //Stop identical ^,/RO5  
FileAccessI fileAccessI = null; //File Access interface (Iaf?J5{  
`$W_R[  
(9Ux{@$o[  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _j< K=){  
{ G 8g<>d{j  
this.sURL = sURL; l'/R&`-n  
this.nStartPos = nStart; B9NWW6S  
this.nEndPos = nEnd; 19E 8'@  
nThreadID = id; inh=WUEW  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 apg=-^L'  
} |mGFts}0o'  
, udTvI  
}bdmomV  
public void run() W-?()dX{  
{ ] 6TATPIr  
while(nStartPos < nEndPos && !bStop) ms*(9l.hOK  
{ _kU:Z  
o<COm9)i  
_'{_gei_P  
try{ amOnqH-(  
URL url = new URL(sURL); ]yK7PH-{L  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BG6B :  
httpConnection.setRequestProperty("User-Agent","NetFox"); eZIhEOF  
String sProperty = "bytes="+nStartPos+"-"; AiEd!u.  
httpConnection.setRequestProperty("RANGE",sProperty); ~Y|*`C_)  
Utility.log(sProperty); GP?M!C,/}k  
DU5c=rxW  
BJM.iXU)[  
InputStream input = httpConnection.getInputStream(); `*_mP<Ag  
//logResponseHead(httpConnection); C8Qa$._  
2+QYhdw  
S|7!{}  
byte[] b = new byte[1024]; WvBc#s-  
int nRead; zNxW'?0Z?  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) c:<005\Bg  
{ kEOS{C%6R  
nStartPos += fileAccessI.write(b,0,nRead); "B3N* R(["  
//if(nThreadID == 1) JBE!j-F  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mS(fgq6  
} UNom-  
r:f[mk"-"A  
S- pV_Ff  
Utility.log("Thread " + nThreadID + " is over!"); 9Uj $K>:  
bDownOver = true; mz,  
//nPos = fileAccessI.write (b,0,nRead); 3I)VHMC  
} D~hg$XzK  
catch(Exception e){e.printStackTrace ();} ="Ho%*@6  
} *AO,^R&e.  
} 'EbWFMjy  
3RYpJAH  
u%}nw :>  
//打印回应的头信息 e1%/26\  
public void logResponseHead(HttpURLConnection con) fGUE<l  
{ >O*IQ[r-  
for(int i=1;;i++) CE#gfP  
{ F`gi_; c  
String header=con.getHeaderFieldKey(i); VH9dleZ  
if(header!=null) /{+y2.{j  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); mRL"nC  
Utility.log(header+" : "+con.getHeaderField(header)); "D63I|O)  
else +jS|2d  
break; C G0 M  
} !W5 (  
} q U%/W|LY  
r^FhTzA=1  
=Xi07_8Ic<  
public void splitterStop() 3Dng 1}  
{ :~2vJzp@?  
bStop = true; 2%LL Sa  
} "P 7nNa  
; <&*rnH  
ar__ Pf6r  
} JmxH"7hTE  
9^oKtkoDZ  
yXSFjcoB  
/* =/s>Q l  
**FileAccess.java s/$?^qtyC  
*//文件访问(定位,写) qh9Z50E9  
package NetFox; 8K:y\1  
import java.io.*; lAb*fafQy  
2oVSn"  
:r{<zd>;  
public class FileAccessI implements Serializable{ 8(pp2rlR  
1S{D6#bE  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 J]{QB^?  
RandomAccessFile oSavedFile; ]^h]t~  
long nPos; ''yB5#^w(  
r_ I5. gK  
r[|Xy>Zj  
public FileAccessI() throws IOException [@VP?74  
{ ^E;kgED5  
this("",0); U#lCj0iUt,  
} A P)L:7w'e  
Bt@^+vH ~  
 _zY# U9  
public FileAccessI(String sName,long nPos) throws IOException &dqLP9 5  
{ C _'%N lJ'  
oSavedFile = new RandomAccessFile(sName,"rw"); .+PI}[g  
this.nPos = nPos; u+Y\6~=+  
oSavedFile.seek(nPos); %|auAq&w  
} tr<Nm6!  
Hx"ob_^'7  
nV"~-On  
public synchronized int write(byte[] b,int nStart,int nLen) e>6y%v;  
{ dBYmiF!+  
int n = -1; t<#TJ>Le  
try{ th  
oSavedFile.write(b,nStart,nLen); O#ai)e_uQk  
n = nLen; ??^5;P{yx  
} GWZ }7ake  
catch(IOException e) `, OG7hg  
{ @5N]ZQ9  
e.printStackTrace (); smlpD3?va  
} ;rF\kX&Jh  
2;k*@k-t  
h;p>o75O  
return n; <c2E'U)X  
} MI/MhkS ?  
94h]~GqNi  
fz|cnU  
} IHB} `e|  
XW[j!`nlk  
7I&&bWB  
/* s2h@~y  
**SiteInfoBean.java J[l7di5  
*/ qX/y5F`  
package NetFox; (/=f6^}  
MLXNZd   
GZEc l'h*  
public class SiteInfoBean { ?4+9fE<Q  
} df W%{  
V3&RJ k=b  
private String sSiteURL; //Site's URL ] ] !VK  
private String sFilePath; //Saved File's Path ). <-X^@  
private String sFileName; //Saved File's Name qraSRK5  
private int nSplitter; //Count of Splited Downloading File gH$ Mr  
_GV:HOBi  
zNs55e.rx  
public SiteInfoBean() xcd#&  
{//nSplitter的缺省值为5 S=MEG+Ad  
//default value of nSplitter is 5 X3{G:H0\p  
this("","","",5); yQ U{ zY  
} .CL[_;}  
/NLui@|R  
h{CL{>d  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =#;3Q~:Jl^  
{ \K5DOM "#  
sSiteURL= sURL; I4'5P}1yp  
sFilePath = sPath; )F}F_Y  
sFileName = sName; Lb!Fcf|h  
this.nSplitter = nSpiltter; ?qP7Y nl  
C_( *>!Z%  
caU0\VS  
} ynq}76 H0k  
N@2dA*T,  
>tYm+coS  
public String getSSiteURL() ohRjvJ'v|  
{ q3mJ782p]  
return sSiteURL; v_BcTzQ0S  
} r)lEofX,g+  
8NxM4$nQX  
B}n,b#,*  
public void setSSiteURL(String value) L9r8BK;  
{ J*r*X.  
sSiteURL = value; -f3p U:G8  
} ?iw!OoZ`  
P 0SQr?W  
\MA+f~)9  
public String getSFilePath() VQ(jpns5  
{ gT3_RUF  
return sFilePath; };mA^xO]j  
} p#&h=,W}  
E-4b[xNj*+  
6 hw=  
public void setSFilePath(String value) |ax3sAg  
{ Ghu#XJB?  
sFilePath = value; h`]Iy  
} A}BVep@D  
_Us#\+]_:  
m!gz3u]rN  
public String getSFileName() ],>@";9u"  
{ ?~l6K(*2  
return sFileName; a+[RS]le  
} HU1h8E$-  
n3T>QgK  
;%B(_c  
public void setSFileName(String value) bk[U/9Z\  
{ F5LuSy+v  
sFileName = value; l>2E (Y|  
} $~~Jw]   
ls_'')yp  
cL-[ZvyVX  
public int getNSplitter() }QN1|mP2  
{ JUsQ,ETn  
return nSplitter; >NO[UX%yP  
} D|lzGt  
spGb!Y`mR  
5 f@)z"j  
public void setNSplitter(int nCount) ?L5zC+c!  
{ pf2[ , v/  
nSplitter = nCount; b[sx_b  
} J}*,HT*  
} qaqBOHI6G  
]S&&|Fc  
i)o2klIkB  
/* ."TxX.&HE  
**Utility.java J &o |QG  
*/ cW~}:;D4  
package NetFox; }'5MK  
!SC`D])l  
bo,_&4?  
public class Utility { szb_*)k  
i#&z2h-b  
.\\DKh%  
public Utility() _mzW'~9wN  
{ O#n8=B4  
Htay-PB }  
jk"`Z<j~  
} 45=bGf#  
r  [9x  
//线程睡眠 n#/_Nz  
public static void sleep(int nSecond) rR$h*  
{ mH54ja2  
try{ 5 z~1Dw  
Thread.sleep(nSecond); __lM7LFL  
} ,oORW/0iS  
catch(Exception e) d)B@x`  
{ @*F"Q1 wI  
e.printStackTrace (); b}OY4~ Y4  
} ~9?cn  
} Av @b!iw+  
Y_Eb'*PY  
//日志 &qLf@1AD  
public static void log(String sMsg) 3T31kQv{  
{ xqXo0  
System.err.println(sMsg); \K_ET> !  
} z(o,m3@v  
AG3>V+k{Lv  
9TU88]  
public static void log(int sMsg) 1;d$#j  
{ E_gD:PPU5  
System.err.println(sMsg); t![7uU.W  
} fs|)l$Rd  
} 2{M^,=^>  
V GL aN%|  
!*/*8re  
/* Nw:GCf-L  
**TestMethod.java yTyj'-4  
*/ &*sP/z  
package NetFox; 68bQ;Dv  
*xc_k"\  
h~A/y!s  
public class TestMethod { *zNYZ#  
V @rI`~$  
%`k6w3qI  
public TestMethod() 9 ^o-EC!_  
{ ///xx/weblogic60b2_win.exe VJ84?b{c W  
try{ pb^i^tA+A  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); m9)p-1y@5  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6f;fx}y  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3yANv?$a  
fileFetch.start(); -1Jg?cPz k  
} +O'3|M  
catch(Exception e){e.printStackTrace ();} gwNq x"  
TH)"wNa  
.=U#eHBdAQ  
} Gk967pC  
gep;{G}  
g6nkZyw  
public static void main(String[] args) K7$x<5+)  
{ yZd +^QN  
new TestMethod(); H!vax)%-\  
} .R`5 Qds*l  
} |yvQ[U~PQ  
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