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http断点续传简单实现(java)

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/* Jp-ae0 Ewa  
**SiteFileFetch.java n"K7@[d  
*/ Z ''P5B;  
package NetFox; YJ16vb9  
import java.io.*; ^]R0d3?>\  
import java.net.*; /?XfVhA:A  
=OZ_\vO  
f|^f^Hu:{  
public class SiteFileFetch extends Thread { }Rux<=cd|  
t2Y~MyT/  
=;/h{ t  
SiteInfoBean siteInfoBean = null; //文件信息Bean D[#\Y+N  
long[] nStartPos; //开始位置 MM8)yCI  
long[] nEndPos; //结束位置 };!c]/,  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 "^D6%I#T  
long nFileLength; //文件长度 NJtB;  
boolean bFirst = true; //是否第一次取文件 !Z'm@,+  
boolean bStop = false; //停止标志 +li^0+3-'  
File tmpFile; //文件下载的临时信息 GyPN)!X@.&  
DataOutputStream output; //输出到文件的输出流 :A{-^qd(  
!yI)3;$*  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) gq@."wHU  
public SiteFileFetch(SiteInfoBean bean) throws IOException N8{>M,  
{ _5Ll L#)  
siteInfoBean = bean; F_Pd\Aq8  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); X*yl% V  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); z0W+4meoH  
if(tmpFile.exists ()) 4 z`5W,  
{ YWZF*,4  
bFirst = false; hB+ t pa  
read_nPos(); T+ t-0k  
} L wu;y@[  
else M1M]]fT0ME  
{ -)I_+N  
nStartPos = new long[bean.getNSplitter()]; mDmWTq\  
nEndPos = new long[bean.getNSplitter()]; j&mL]'Zy  
} PYf`a`dH  
A{o{o++  
v: 0i5h&M  
Ji[w; [qL  
} g:clSN,  
'~cEdGD9H  
V V4_  
public void run() >lW*%{|b$^  
{ C/Z"W@7#;  
//获得文件长度 TatyD**(  
//分割文件 yEny2q}  
//实例FileSplitterFetch -&A[{m<,>  
//启动FileSplitterFetch线程 G9[-|[j^N  
//等待子线程返回 Jr9}'l8  
try{ .0|J+D  
if(bFirst) yW&i Uh=0  
{ j&pgq2Kl  
nFileLength = getFileSize(); .2P?1HpK  
if(nFileLength == -1) E)E!  
{ Ttj5% ~  
System.err.println("File Length is not known!"); 'x0t, ;g  
} <Gw<(M  
else if(nFileLength == -2) gZUy0`E  
{ ;hvXFU  
System.err.println("File is not access!"); hF1/=;>  
} O?WaMfS[1  
else VfwD{+ 5  
{ V"ZbKV +[  
for(int i=0;i<nStartPos.length;i++) 0R]CI  
{ bsr y([N>w  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); A!kyga6F5  
} Mt Z(\&~  
for(int i=0;i<nEndPos.length-1;i++) QBy*y $  
{ ,H?p9L; qp  
nEndPos = nStartPos[i+1]; jb2:O,+!  
} eQx"nl3U%  
nEndPos[nEndPos.length-1] = nFileLength; #c>MUC(?s:  
} h<.[U $,  
} !q/lgpEi  
[mPdT^h  
20qVzXi  
//启动子线程 Q ?t  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [VW;L l  
for(int i=0;i<nStartPos.length;i++) zFr}$  
{ 9%qMZP0]  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NLl~/smMS  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (r4VIlap  
nStartPos,nEndPos,i); iL, XBoE  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Fzs'@*  
fileSplitterFetch.start(); Fc~w`~tv  
} 5uer [1A  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }A7qIys$4  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /8>/"Z2S  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 0Y 2^}u@5  
nEndPos = " + nFileLength); [BBKj)IK  
// fileSplitterFetch[nPos.length-1].start(); af(JoX*U  
e;5Lv9?C8  
rk|(BA  
//等待子线程结束 %6'D!H?d  
//int count = 0; )1}g7:  
//是否结束while循环 J#DcT@  
boolean breakWhile = false; HJR<d&l;p  
zYdtQjv  
bl?%:qb.V  
while(!bStop) )^Pvm  
{ jPNfLwVkl:  
write_nPos(); i_Z5SMZ  
Utility.sleep(500); P{!:pxu[  
breakWhile = true; YnWl'{[ C  
mN 6`8 [  
}%ThnFFBw  
for(int i=0;i<nStartPos.length;i++) Y0\\(0j64  
{ I JY5wP1"  
if(!fileSplitterFetch.bDownOver) i q:Q$z&  
{ 5]l7Z35  
breakWhile = false; PAU+C_P  
break; [B3aRi0AQ  
} BpG'e-2  
} FT>~ES]cQd  
if(breakWhile) TrU@mYnE  
break; je4&'vyU  
bV*zMoD#  
A9Wqz"[  
//count++; ('q vYQ  
//if(count>4) az;jMnPpR5  
// siteStop(); <]^;/2 .B  
} 6QXQ<ah"  
gQ[^gPWP"  
9[{>JRm.  
System.err.println("文件下载结束!"); `L#?eQ{  
} LIC~Kehi  
catch(Exception e){e.printStackTrace ();} l\;mP.!  
} Jx$#GUl#j  
)?&kQ^@v  
Y;F R"~^  
//获得文件长度 ?s)sPM?  
public long getFileSize() 1`]IU_)1B  
{ <-:@} |br  
int nFileLength = -1;  7EP|X.  
try{ rHgdvDc  
URL url = new URL(siteInfoBean.getSSiteURL()); `]P5,  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +`zi>=  
httpConnection.setRequestProperty("User-Agent","NetFox"); s.^9HuM  
#2R%H.*t  
\41)0,sEy  
int responseCode=httpConnection.getResponseCode(); 1DLG]-j}  
if(responseCode>=400) K6{bYho  
{ C%_  
processErrorCode(responseCode); (}1v^~FXj  
return -2; //-2 represent access is error - (_e=3$  
} p?$G>nkdq  
)YMlF zYr  
NJ)2+  
String sHeader; 3U"')  
04PoBv~g  
.k,Jt+  
for(int i=1;;i++) mzE$aFu8  
{ Mq :'-`  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /;NE]{K  
//Utility.log(in.readLine()); Bd9hf`% 2  
sHeader=httpConnection.getHeaderFieldKey(i); +lgF/y6  
if(sHeader!=null) 3V Mh)  
{ CQjZAv  
if(sHeader.equals("Content-Length")) [s{r$!Gl  
{ Y3$PQwn .P  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); dH2]ZE0V  
break; gO:Z6}3vM  
} 3$N %iE6  
} ^jha:d  
else i<wU.JX&h  
break; B >u,)  
} D<bU~Gd,P  
} ,+/9K)X  
catch(IOException e){e.printStackTrace ();} [Ba2b: l6v  
catch(Exception e){e.printStackTrace ();} ]\RSHz  
{ LT4u ]#  
Z-t}6c'Kg  
Utility.log(nFileLength); :-u-hO5*8  
`e?;vA&  
G?1x+H;o5  
return nFileLength; qTTn51  
} 9R@abm,I  
m c\ C  
2#b<d?"  
//保存下载信息(文件指针位置) IQw %|^  
private void write_nPos() 974eY  
{ PPCTc|G  
try{ GL 5^_`n  
output = new DataOutputStream(new FileOutputStream(tmpFile)); i9;27tT~<  
output.writeInt(nStartPos.length); r2SJp@f  
for(int i=0;i<nStartPos.length;i++) uGa(_ut  
{ 'l' X^LMD  
// output.writeLong(nPos); Qb?y@>-[  
output.writeLong(fileSplitterFetch.nStartPos); AGEZ8(h  
output.writeLong(fileSplitterFetch.nEndPos); ~)wwX:;B_  
} h7EUIlh"  
output.close(); 7~ *;=,mw  
} a*6wSAA )  
catch(IOException e){e.printStackTrace ();} R5K-KSvW  
catch(Exception e){e.printStackTrace ();} R2N^'  
} 13.{Y)  
bk7^%O>  
U+.PuC[3  
//读取保存的下载信息(文件指针位置) .>kccLr:z  
private void read_nPos() a: yB%:2  
{ XhE$&Ff  
try{ np-T&Pz2  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); K}PvrcO1  
int nCount = input.readInt(); : 'd76pM-  
nStartPos = new long[nCount]; emv;m/&8  
nEndPos = new long[nCount]; (|<h^] y3  
for(int i=0;i<nStartPos.length;i++) <Spr6U9p7  
{ 5 6Sh  
nStartPos = input.readLong(); h-r6PY=i  
nEndPos = input.readLong(); B:O+*3j  
} '!wPnYT@D  
input.close(); |"CJ  
} AZxrJ2G  
catch(IOException e){e.printStackTrace ();} 0{0;1.ZP  
catch(Exception e){e.printStackTrace ();} PyC;f8n'(  
} "u(S2'DW'(  
wTTTrk  
>`hSye{  
private void processErrorCode(int nErrorCode) Gva}J 6{  
{ ?eL='>Ne  
System.err.println("Error Code : " + nErrorCode); r7Nu>[r5  
} j6tP)f^tD  
k40Ep(M}  
vIVw'Z(g}  
//停止文件下载 # #k #q=4  
public void siteStop() e=gboR  
{ z}> 4,d  
bStop = true; u}Ei_ O<z  
for(int i=0;i<nStartPos.length;i++) c8#T:HM|`  
fileSplitterFetch.splitterStop(); GFd Z`i  
ZR/R'prW  
5mI?pfm  
} 6Cl+KcJH  
} v]WH8GI  
//负责部分文件的抓取 x*unye7  
**FileSplitterFetch.java ElQJ\%  
*/ uQ:Qb|  
package NetFox; AA))KBXq  
>vQ6V'F  
_&W0e}4  
import java.io.*; <TI3@9\qXE  
import java.net.*; G%2P  
k(zs>kiP  
GhqgRzX  
public class FileSplitterFetch extends Thread { R(:  4s  
=QrA0kQR  
Rr+qg t;f5  
String sURL; //File URL iY0,WT}&n  
long nStartPos; //File Snippet Start Position 13ipaz  
long nEndPos; //File Snippet End Position n&_YYEHx  
int nThreadID; //Thread's ID @<vF]\Ce  
boolean bDownOver = false; //Downing is over _/|8%])  
boolean bStop = false; //Stop identical i[^k.W3gf  
FileAccessI fileAccessI = null; //File Access interface 1KW3l<v-6  
3hc#FmLr2b  
`6rrXU6|  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException T|;^.TZ  
{ McEmd.S<n  
this.sURL = sURL; }l.KpdRT2  
this.nStartPos = nStart; 7}<Sg  
this.nEndPos = nEnd; 'oC$6l'rQ  
nThreadID = id; )*!1bgXQ  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 54=}GnZN  
} jo_o` j  
3QCMK^#Z:  
ewo*7j4*  
public void run() S&n[4*  
{ q z=yMIy=  
while(nStartPos < nEndPos && !bStop) b![t6-f^z  
{  "\`>2  
"VV914*z  
DXKyRkn6e  
try{ Ip>^O/}$1  
URL url = new URL(sURL); h=hoV5d@  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DeA@0HOxh  
httpConnection.setRequestProperty("User-Agent","NetFox"); }g}6qCv7  
String sProperty = "bytes="+nStartPos+"-"; a ]>VZOet  
httpConnection.setRequestProperty("RANGE",sProperty); >/b^fAG  
Utility.log(sProperty); <E"*)Oi  
-dg}BM  
u-lrTa""z  
InputStream input = httpConnection.getInputStream(); N].4"0Jv-D  
//logResponseHead(httpConnection); KZECo1  
,SAbC*nq  
GXO4x|08F  
byte[] b = new byte[1024]; *0O<bm  
int nRead; O-Dc[t%  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) gyC^K3}  
{ otU@X 3<_  
nStartPos += fileAccessI.write(b,0,nRead); _]P a>8X*  
//if(nThreadID == 1) _=uviMuE  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V R"8Di&)  
} MM7"a?y)  
=Qyqfy*@D?  
6mwvI4)  
Utility.log("Thread " + nThreadID + " is over!"); .Nc_n5D6  
bDownOver = true; Pow|:Lau!  
//nPos = fileAccessI.write (b,0,nRead); ,`<]>;s  
} Bgf=\7;5  
catch(Exception e){e.printStackTrace ();} TNx_Rc}  
} \F[n`C"Is  
} ?k"0w)8  
7 xUE,)?  
mIRAS"Q!m  
//打印回应的头信息 C}9Kx }q  
public void logResponseHead(HttpURLConnection con) .U<F6I:<md  
{ C]/&vh7ta  
for(int i=1;;i++) FK6K6wU52m  
{ 6Hda]y  
String header=con.getHeaderFieldKey(i); #aa1<-&H  
if(header!=null) \OP9_J(*  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _y>}#6B  
Utility.log(header+" : "+con.getHeaderField(header)); 'v\j.j/i  
else W;.{]x.0  
break; .`Sw,XL5  
} :xM}gPj"  
} YhS{$ Z  
mzu<C)9d,  
z<t>hzl 7  
public void splitterStop() <E SvvTf  
{ |!oXvXU  
bStop = true; lO[E[c G  
} 0#<WOns1   
uNy!< u  
n_J5zQJ  
} Jns/v6  
]Ym=+lgi  
%0lf  
/* VxkEez'|  
**FileAccess.java X CzXS.  
*//文件访问(定位,写) +|9f%f6vp  
package NetFox; y[7C% Wj  
import java.io.*; /,X7.t_-  
Uh}+"h5  
nW11wtiO.  
public class FileAccessI implements Serializable{ g**5z'7  
^Wm*-4  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 N2T&,&, t  
RandomAccessFile oSavedFile; JxHv<p[  
long nPos; ).Q[!lly   
'=p?  
BR3wX4i\  
public FileAccessI() throws IOException -n-Z/5~ X  
{ (V!0'9c  
this("",0); PGkCOmq   
} C;ptir1G;  
1) 'Iu`k/  
[EER4@_  
public FileAccessI(String sName,long nPos) throws IOException 7/ t:YBR  
{ {<!hlB  
oSavedFile = new RandomAccessFile(sName,"rw"); 7C?E z%a@  
this.nPos = nPos; Tv1]v.  
oSavedFile.seek(nPos); ;5N41_hG  
} ^;4YZwW5w  
a5)JkC  
1U'ZVJ5bpK  
public synchronized int write(byte[] b,int nStart,int nLen) fq=:h\\G  
{ AC'lS >7s  
int n = -1; >P<'L4;  
try{ zC#%6@P\  
oSavedFile.write(b,nStart,nLen); 2 ZK%)vq0  
n = nLen; m2Q$+p@  
} i\  "{#  
catch(IOException e) EWO /u.z  
{ @%:E  }  
e.printStackTrace (); h"r!q[MN o  
} @<a|  
M|H 2kvl  
83Uw  
return n; Y0}4WWV  
} i(Vm!Y82  
7VY8CcL  
x%pRDytA  
} onib x^Fcd  
NNmM#eB:4  
S}b~_}  
/* F )7j@h^  
**SiteInfoBean.java 9$wAm89  
*/ ##GY<\",;  
package NetFox; { m'AY)  
c})wD+1  
vzG ABP  
public class SiteInfoBean { e,"FnW  
3e *-\TP-  
) P%4:P  
private String sSiteURL; //Site's URL E<k ^S{  
private String sFilePath; //Saved File's Path fdLBhe#9M  
private String sFileName; //Saved File's Name 9(Jy0]E~  
private int nSplitter; //Count of Splited Downloading File R(`]n!V2  
gs>A=A(VYf  
gvlFumg2  
public SiteInfoBean() #2N_/J(U  
{//nSplitter的缺省值为5 X|'2R^V.  
//default value of nSplitter is 5 MnS+nH!d  
this("","","",5); =+\$e1Mb*  
} O+b6lg)q  
AOAO8%|I  
\OY}GRKt  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) j76%UG\Ga  
{ K[]K53Nk  
sSiteURL= sURL; v^TkDf(Oz  
sFilePath = sPath; %/!+(7 D  
sFileName = sName; <]'|$8&jY  
this.nSplitter = nSpiltter; V)h y0_  
~ aA;<#  
t#~XLCE  
} _*n)mlLln  
e=L*&X  
0qR$J  
public String getSSiteURL() ^cn@?k((A  
{ Yt*vqm[WV  
return sSiteURL; 4DM*^=9E  
} d- kZt@DL=  
OpUA{P  
Y;eoT J  
public void setSSiteURL(String value) Tyd h9I  
{ 6]ZO'Nwo  
sSiteURL = value; |6*Va%LYO-  
} 0 u2Ny&6w  
9(OAKUQ  
ju.OW`GM  
public String getSFilePath() K_&_z  
{ vpV$$=Qwp  
return sFilePath; Qsji0ikG  
} 37jQ'O U  
LihdZ )  
N iISJWk6'  
public void setSFilePath(String value) `;/XK,m-  
{ uY]T:UVk  
sFilePath = value; ]5)"gL%H`  
} `I#`:hj  
lRH0)5`  
LD_M 3 P  
public String getSFileName() /ao<A\KR  
{ 7 Kjj?~RA  
return sFileName; %"+4 D,'l  
}  Fs)  
qRl/Sl#F  
4m\([EO  
public void setSFileName(String value) DJ|BM+  
{ *m&%vj.Kc  
sFileName = value; jzMg'z/@J  
} `)2[ST  
oLw|uU-|  
gmDR{loX  
public int getNSplitter() h1c{?xH2r  
{ K"^cq~   
return nSplitter; O{u[+g  
} !t% Q{`p  
qK,V$l(4#  
1!1DuQ  
public void setNSplitter(int nCount) = hhvmo  
{ ,2_w=<hq  
nSplitter = nCount; F9O`HFVK  
} lvPpCAXY  
} wE4;Rk1  
vcM~i^24)  
:~er h}~ps  
/* gCL{Cw  
**Utility.java <r3Jf}%tT  
*/ W #47Cz  
package NetFox; ~b#OFnyG  
PT05DH  
ftaBilkjp  
public class Utility { :G0+;[?N  
4i`S+`#  
>j:|3atb  
public Utility() cd+^=esSO  
{ DyIV/  
-!~vA+jw1  
kF?S 2(vH  
} b|6!EGh  
SBz/VQ  
//线程睡眠 >>j+LRf*  
public static void sleep(int nSecond) #4N >d~  
{ qw2)v*Fn  
try{ XECikld>  
Thread.sleep(nSecond); s6/cL|Ex  
} 2m_H*1 HJ  
catch(Exception e) Rf?%Tv0\  
{ /`}6rXnw9  
e.printStackTrace (); mYzcVhV  
} >] -<uT_  
} p7$3`t 6u  
)tvc/)&A}  
//日志 7PA=)a\  
public static void log(String sMsg) A6Q c;v+  
{ ?R282l  
System.err.println(sMsg); Lrlk*   
} FCAJavOGH  
H4 =IY  
U1jSUkqb  
public static void log(int sMsg) @2?=3Wf  
{ ]1tN|ODY*W  
System.err.println(sMsg); PF`:1;P U  
} m|mG;8}pI  
} hwp/jO:7\  
wa2~C [  
Hva{A #  
/* a}w&dE$!-  
**TestMethod.java 3<3t;&e  
*/ Z@u ;Z[@  
package NetFox; ]o `4Z"  
?`"<DH~:0B  
m EFWo  
public class TestMethod { [?|5 oaK  
pj+tjF6Np  
=/m}rcDN  
public TestMethod() PYaOH_X.  
{ ///xx/weblogic60b2_win.exe }^Z< dbt  
try{ t:disL& !E  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6kC)\ uy  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `u$24h'!  
SiteFileFetch fileFetch = new SiteFileFetch(bean); CM"s9E8y  
fileFetch.start(); ;2BPPZ  
} f)WPOTEY  
catch(Exception e){e.printStackTrace ();} pRmEryR(U  
sY_fq.Z  
WFXx70n  
} ${e -ffyy  
ijg,'a~3E  
w2' 3S#nZ  
public static void main(String[] args) |NXFla  
{ ypxC1E  
new TestMethod(); S;BP`g<l=  
} N*? WUn9]  
} CO7CNN  
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