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http断点续传简单实现(java)

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/* 0k];%HV|  
**SiteFileFetch.java &>!WhC16  
*/ i n^Rf` "  
package NetFox; n,Z B-"dW  
import java.io.*; cX64 X  
import java.net.*; m;v/(d>  
n-cz xq%n  
p:,(r{*?  
public class SiteFileFetch extends Thread { 05<MsxB"w  
nsq7,%5  
E+65  
SiteInfoBean siteInfoBean = null; //文件信息Bean 415 95x:  
long[] nStartPos; //开始位置 /}]Irj4m  
long[] nEndPos; //结束位置 'WUevPmt  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 uQ;b'6Jcp  
long nFileLength; //文件长度 R ks3L  
boolean bFirst = true; //是否第一次取文件 ijYSYX@  
boolean bStop = false; //停止标志 d.7pc P  
File tmpFile; //文件下载的临时信息 FafOd9>AO  
DataOutputStream output; //输出到文件的输出流 Dl3Df u8  
]< 0|"NL  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) S*o%#ZJN  
public SiteFileFetch(SiteInfoBean bean) throws IOException &oWdBna"_  
{ Jmln*,Ol7  
siteInfoBean = bean; nnU &R  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Um k9  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); w*})ZYIUT  
if(tmpFile.exists ()) 'w+T vOB  
{ `]^JOw5o  
bFirst = false; <B;l).[6  
read_nPos(); +G3&{#D ?  
} s!q6OVJ-  
else [Hn4&PET  
{ RNyw`>  
nStartPos = new long[bean.getNSplitter()]; 1 )aB']K%  
nEndPos = new long[bean.getNSplitter()]; N U*6MT4  
} `N~;X~XFk  
7P`|wNq  
zR'lQ<u  
Tn+6:<OFdO  
} '3f"#fF6  
,%+i}H,3  
g/b_\__A  
public void run() 9PA\Eo|Yb  
{ 7_WD)Y2yS  
//获得文件长度 a_YE[6  
//分割文件 'IweN  
//实例FileSplitterFetch n"dC]&G'  
//启动FileSplitterFetch线程 Uhc2`r#q  
//等待子线程返回 \v7M`! &  
try{ igp[cFN  
if(bFirst) 0xVue[ep  
{ m4{F-++dk  
nFileLength = getFileSize(); /jQW4eW0  
if(nFileLength == -1) 9-Bp=M  
{ dnVl;L8L3  
System.err.println("File Length is not known!"); O_#Ag K<A  
} XV+s 5 C  
else if(nFileLength == -2) }vkrWy^  
{ +53 Tf  
System.err.println("File is not access!"); P SDzs\s  
} Ycypd\q/  
else %  (R10G  
{ V-U,3=C  
for(int i=0;i<nStartPos.length;i++) )A9K9pZj  
{ 0 !yvcviw  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); -o<L%Y<n2  
} M7 &u_Cn?  
for(int i=0;i<nEndPos.length-1;i++) Ml` f+$  
{ h_ef@ZwSw  
nEndPos = nStartPos[i+1]; iha{(-  
} 0[@ 9f1Nk4  
nEndPos[nEndPos.length-1] = nFileLength; RwMK%^b  
} ps1ndGp~#  
} $}0q=Lg%wv  
D;.O#bS  
"Zd4e2>{M\  
//启动子线程 OJ ng  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &K5wCNX1  
for(int i=0;i<nStartPos.length;i++) %-!ruc"}  
{ (3`Q`o;  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5;5;bBo~  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7q*L-Xe]k  
nStartPos,nEndPos,i); vdrV)^  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qt5CoxeJ  
fileSplitterFetch.start(); ,Ju f  
} :9N~wd  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), EotZ$O=  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); "/Fp_g6#:  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", sXp>4MomV  
nEndPos = " + nFileLength); =s`\W7/;{-  
// fileSplitterFetch[nPos.length-1].start(); WJBi#(SY  
ZzPlIl}\  
dxbP'2~  
//等待子线程结束 ~TC z1UWV  
//int count = 0; f^il|Obzl  
//是否结束while循环 tL(B gku9  
boolean breakWhile = false; I#QBJ#  
<@xp. Y  
O1IR+"0  
while(!bStop) vt}+d StUm  
{ tbD>A6&VM}  
write_nPos(); sh(G{Yz@  
Utility.sleep(500); X=)Ue  
breakWhile = true; 2C^/;z  
tjc3;9  
.VN"j  
for(int i=0;i<nStartPos.length;i++) mxsmW  
{ e`ti*1]q  
if(!fileSplitterFetch.bDownOver) v 0mc1g+9  
{ z/u;afB9q  
breakWhile = false; |r5 np  
break; AFO g*{1  
} $6.CN#  
} <RY5ZP  
if(breakWhile) =jIB5".  
break; e eb`Ao  
FOiwB^$ >  
1 zIFQ@  
//count++; ;n_|t/=  
//if(count>4) )$K )`uqb  
// siteStop(); aOWW ..|  
} y?j#;n0  
|D<J9+  
3jQy"9f  
System.err.println("文件下载结束!"); hN*,]Z{  
} %Cbqi.iuQ  
catch(Exception e){e.printStackTrace ();} gw_]Y^U  
} f2]O5rX p  
wqE+hKs,  
"eH.<&  
//获得文件长度 \sc's7  
public long getFileSize() caD|*.b  
{ Z~6PrM-M  
int nFileLength = -1; \wb0%> 0  
try{ 4iC=+YUn  
URL url = new URL(siteInfoBean.getSSiteURL()); UC*\3:>'n  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cz.,QIt_  
httpConnection.setRequestProperty("User-Agent","NetFox"); %$ ^ eY'-'  
Bxf]Lu,\U@  
RA ER\9i  
int responseCode=httpConnection.getResponseCode(); \ ~uY);  
if(responseCode>=400) C|g]Y 7  
{ Z_WJgH2c  
processErrorCode(responseCode); k3VRa|Y")  
return -2; //-2 represent access is error %(d0`9  
} 17) `CM$<[  
){FXonVP  
ZB'ms[  
String sHeader; )D8V;g(7F  
bU{lV<R,  
BW5!@D2  
for(int i=1;;i++) Tq,xW  
{ 8iXt8XY3  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); up )JU [  
//Utility.log(in.readLine()); `\M}~  
sHeader=httpConnection.getHeaderFieldKey(i);  r NT>{  
if(sHeader!=null) T@gm0igW/;  
{ t(r}jU=qw  
if(sHeader.equals("Content-Length")) 35 3*D%8  
{ ?7cT$/4  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .NRSBk  
break; [`_-;/Gx2  
} $I4:g.gKpG  
} i564<1`x  
else &A)u!l Ue  
break; ]v|n'D-?  
} OiJz?G:m  
} -;W`0 k^  
catch(IOException e){e.printStackTrace ();} S0jYk (  
catch(Exception e){e.printStackTrace ();} BaXf=RsZ  
6sz:rv}  
Y9ipy_@_?  
Utility.log(nFileLength); B4{clI_i  
L)-1( e<x  
 mm9xO%  
return nFileLength; Fz1K*xx'  
} XTS%:S  
4#Id0['  
#@8JYzMq%  
//保存下载信息(文件指针位置) {L.=)zt>  
private void write_nPos() &KP JB"0L  
{ 6o=Q;Mezl  
try{ ^rssZQKY[  
output = new DataOutputStream(new FileOutputStream(tmpFile)); rls\3 R(jt  
output.writeInt(nStartPos.length); 4elA<<  
for(int i=0;i<nStartPos.length;i++) U_61y;Q"  
{ < +X,oxg  
// output.writeLong(nPos); :WHbwu,L$  
output.writeLong(fileSplitterFetch.nStartPos); >A ?{cbJ  
output.writeLong(fileSplitterFetch.nEndPos); K3-Cuku  
} {/}p"(^  
output.close(); <MzXTy3\  
} a1 .+L  
catch(IOException e){e.printStackTrace ();} &)GlLpaT  
catch(Exception e){e.printStackTrace ();} qJq!0F  
} ]7J*(,sp  
|)+45e  
)| 0(#R  
//读取保存的下载信息(文件指针位置) ewVks>lbz  
private void read_nPos() k293 wS  
{ (Z?g^kjq)  
try{ tqzr +  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g-DFcwO,V  
int nCount = input.readInt(); w<Ot0&&  
nStartPos = new long[nCount]; I;+>@Cn(g<  
nEndPos = new long[nCount]; y@9ifFr  
for(int i=0;i<nStartPos.length;i++) + ;_0:+//  
{ k`NXYf:  
nStartPos = input.readLong(); _`+2e-  
nEndPos = input.readLong(); >N-l2?rE  
} ]^I[SG,  
input.close(); 36\_Y?zx%  
} PYr'1D'  
catch(IOException e){e.printStackTrace ();} gzEcdDD  
catch(Exception e){e.printStackTrace ();} ]BaK8mPl  
}  wkKSL  
]:svR@E  
T l8`3`e  
private void processErrorCode(int nErrorCode) iJS7g  
{ $8`"  
System.err.println("Error Code : " + nErrorCode); KO[,C[;|j  
} Xo3@-D_c!c  
V#X<Yt  
qO[_8's8  
//停止文件下载 ;Q0H7)t:  
public void siteStop() ^9 ^DA!'  
{ ~L:H]_8F l  
bStop = true; /6:qmh2  
for(int i=0;i<nStartPos.length;i++) RO[6PlrRN  
fileSplitterFetch.splitterStop(); !Y10UmMu  
#wp~lW9!s9  
h}Lrpr2r  
} f([d/  
} }#6~/ W  
//负责部分文件的抓取 {xf00/  
**FileSplitterFetch.java Bo8NY!  
*/ >Q:h0b_$U  
package NetFox; R#ZO<g%'  
 vUR gR  
i5SDy(?r  
import java.io.*; D B(!*6#?  
import java.net.*; } ^2'@y!(  
 %e(DPX  
$hy0U_}6  
public class FileSplitterFetch extends Thread { "(Nt9K%P)  
d<[L^s9  
\- 8aTF  
String sURL; //File URL t \-|J SZ  
long nStartPos; //File Snippet Start Position a|z@5r%  
long nEndPos; //File Snippet End Position J3$@: S'  
int nThreadID; //Thread's ID yB|1?L#  
boolean bDownOver = false; //Downing is over Y]DC; ,  
boolean bStop = false; //Stop identical klnk{R.>|  
FileAccessI fileAccessI = null; //File Access interface -_= m j  
Ey% KbvNv  
e-#V s{?|r  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException g}pD%  
{ D 4sp+   
this.sURL = sURL; @@cc /S  
this.nStartPos = nStart; ^U##9KkP  
this.nEndPos = nEnd; t9)S^: 0  
nThreadID = id; yW&ka3j\  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @M"( r"ab  
} M0$E_*  
i8S=uJ]n  
5 v^tPGg4  
public void run() =_CH$F!U  
{ / }*}r  
while(nStartPos < nEndPos && !bStop) d.HcO^  
{ =}YX I  
MjWxfW/  
uW2  q\  
try{ qae|?z  
URL url = new URL(sURL); d{"@<0i?  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G}g;<,g~  
httpConnection.setRequestProperty("User-Agent","NetFox"); )9_W"'V  
String sProperty = "bytes="+nStartPos+"-"; 7@\.()  
httpConnection.setRequestProperty("RANGE",sProperty); [`b,SX x  
Utility.log(sProperty); bs?\ )R5/  
\}v@!PQl  
cZ|*Zpk  
InputStream input = httpConnection.getInputStream(); 4KtD  k  
//logResponseHead(httpConnection); jVd`J  
k>mXh{ (  
-Pp{aF e  
byte[] b = new byte[1024]; Zf3(! a[  
int nRead; hmo4H3g!N  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) U&1O  
{ py:L-5  
nStartPos += fileAccessI.write(b,0,nRead); 5g-1pzP9  
//if(nThreadID == 1) h#UPU7;  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \\ R<HuTY  
} ck `td%  
j07A>G-=  
a+v.(mCG  
Utility.log("Thread " + nThreadID + " is over!"); 6bj77CoB  
bDownOver = true; Dj=$Q44  
//nPos = fileAccessI.write (b,0,nRead); #s\yO~F-  
} ? }ff O  
catch(Exception e){e.printStackTrace ();} 9 AD*  
} /<T{g0s  
} w8q 2f-K-  
eVMnI yr  
$HOe){G  
//打印回应的头信息 GBS+ 4xL|  
public void logResponseHead(HttpURLConnection con) PyI"B96gz  
{ au=@]n#<(  
for(int i=1;;i++) X*7VDt=  
{ tIV9Y=ckr0  
String header=con.getHeaderFieldKey(i); |ul{d|  
if(header!=null) &QQ6F>'T  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); UnVa`@P^:G  
Utility.log(header+" : "+con.getHeaderField(header)); 7ieAd/:_  
else Ed0}$ b  
break; d7X7_  
} j)ln"u0R^B  
} @>ys,dy  
LrdED[Z  
,qB@agjvo<  
public void splitterStop() ?)<zzL",  
{ %'. x vC  
bStop = true; ,bM):  
} q3v5gz^t  
\AI-x$5R*  
Ke#Rkt  
} M;AvOk|&  
XLYGhM  
M'X,7hZ  
/* <f)T*E^5%  
**FileAccess.java CO, {/  
*//文件访问(定位,写) @Wm:Rz  
package NetFox; +o,f:Ih  
import java.io.*; yZoJD{'?Sw  
5mL4Zq"  
w4Hq|N1-Y  
public class FileAccessI implements Serializable{ kbH@h2Ww  
l  LBzY`j  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 LV$Ko_9eA  
RandomAccessFile oSavedFile; 5TeGdfu @  
long nPos; 5K&A2zC|  
g&. OJ  
IY!8j$'|  
public FileAccessI() throws IOException >@a7Zzl0H  
{ V+U89j1g  
this("",0); -I*vl  
} I^n,v) 8  
K0I.3| 6C  
~(Q#G" t  
public FileAccessI(String sName,long nPos) throws IOException )@tHS-Jf  
{ qrZ3`@C4k  
oSavedFile = new RandomAccessFile(sName,"rw"); Cd6th F)  
this.nPos = nPos; b8%TwYp  
oSavedFile.seek(nPos); m' |wlI[lq  
} :7Uv)@iUk  
4OAR ["f  
@1bl<27  
public synchronized int write(byte[] b,int nStart,int nLen) "So "oT1  
{ ~GJ;;v1b2  
int n = -1; f?16%Rk<  
try{ u35"oLV6}#  
oSavedFile.write(b,nStart,nLen); nC?Lz1re  
n = nLen; i ;Kax4k  
} BbL]0i  
catch(IOException e) /m^G 99N  
{ E1w8d4P,G  
e.printStackTrace (); ,S`F xJcE  
} tt6GtYrC 1  
g"c7$  
i]@k'2N  
return n; @W==)S%O  
} /+ais 3  
Oc.8d<  
p"H /N_b4  
} cBOt=vg,5  
(4C)] RHQ  
!\Cu J5U  
/* hl)jE 06  
**SiteInfoBean.java 4L97UhLL  
*/ {%&04yq+  
package NetFox; O@dK^o  
zF? 6"  
~6QV?j  
public class SiteInfoBean { <F-IF7>a  
,[dvs&-*  
j+gh*\:q  
private String sSiteURL; //Site's URL 7xWJw  
private String sFilePath; //Saved File's Path 7*WO9R/  
private String sFileName; //Saved File's Name O9ro{ k  
private int nSplitter; //Count of Splited Downloading File vD/l`Ib:  
#~qza ETv,  
uFlf#t =  
public SiteInfoBean() wM-H5\9n  
{//nSplitter的缺省值为5 1L?W+zMO  
//default value of nSplitter is 5 P"@^BQ4  
this("","","",5); K_.|FEV  
} LFYSur8  
FBzsM7]j  
VOg'_#I  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) zx+}>(U\U  
{ [`bK {Dq2  
sSiteURL= sURL; 2<'ol65/c  
sFilePath = sPath; 4((p?jb C  
sFileName = sName; bhsCeH  
this.nSplitter = nSpiltter; txX>zR*)  
?UeV5<TewS  
mGF)Ot R  
} wCj)@3F  
WK#%G  
IfI:|w}:"r  
public String getSSiteURL() =k1sF3.V'c  
{ K]dR%j  
return sSiteURL; 6J$I8b#/  
} Vk[M .=J  
]<Q&  
wMCgL h\wi  
public void setSSiteURL(String value) @s,kx.S  
{ KhL%ov  
sSiteURL = value; =xSf-\F  
} (FGH t/!  
taO(\FOm  
+u&3pK>f  
public String getSFilePath() <HpUP!q8v  
{ hVd_1|/X  
return sFilePath; u6MU @?  
} )?6%d  
7$IR^  
8 ~Pdr]5  
public void setSFilePath(String value) w2lO[o~x}  
{ z('t#J!b  
sFilePath = value; HoeW6UV  
} E7/i_Xkk  
X7tBpyi  
Q=#FvsF#z3  
public String getSFileName() )YwLj&e4tf  
{ .%M80X{5~  
return sFileName; 9}a&:QTHR  
} ]bstkf}~u  
@V^5_K  
e :T9f('  
public void setSFileName(String value) f*p=j(sF  
{ [N"=rY4G  
sFileName = value; N]\)Ok  
} Wq}W )E  
Ev3,p`zS._  
lW4 6S  
public int getNSplitter() F9A5}/\  
{ l?Ls=J*  
return nSplitter; bPV;"  
} jI<_(T  
4sC)hAx&f  
tOo\s&j  
public void setNSplitter(int nCount) \+x#aN\  
{ = U[$i"+  
nSplitter = nCount; -MORd{GF  
} D r"PS >.  
} x&$8;2&.  
%/SHB  
g!z &lQnZ  
/* _:Jma  
**Utility.java m';4`Y5-  
*/ l7Wdbx5x0  
package NetFox; 1KjzKFnb  
G'wyH[ d/  
 sHOBT,B  
public class Utility {  "Id 1H  
4E$d"D5]>p  
6LqF*$+$`  
public Utility() JZJb&q){  
{ s%A?B 8,  
KHM,lj*  
*q@3yB}  
} /4upw`35]  
at\$ IK_  
//线程睡眠 Oe;1f#` 5  
public static void sleep(int nSecond) V}FH5z |  
{ #E#@6ZomT  
try{ 6p.y/LMO  
Thread.sleep(nSecond); ViUx^e\  
} a|k*A&5u2  
catch(Exception e) JZE<oQ_Jm  
{ )r(e\_n  
e.printStackTrace (); /2 qxJvZ  
} =>O{hT ^F  
} Ml )<4@  
n} ]gAX  
//日志 &M=15 uCK  
public static void log(String sMsg) a;&0u>  
{ >;}(? +|f  
System.err.println(sMsg); '"h}l`  
} m &[(xVM  
K1o&(;l8G  
Ix0#eoj  
public static void log(int sMsg) [I[*?9}$"  
{ ^__ P;Gr`  
System.err.println(sMsg); R?J8#JPXD  
} {#&D=7LP  
} 9QeBz`lm)  
,ruL7|T&  
3Y}X7-|)Z  
/* J|z>5Z  
**TestMethod.java qd7 86~  
*/ X_0Ta_u?T  
package NetFox; e(NpX_8  
V!Q1o!J  
9Xv>FVG!  
public class TestMethod { Jt3]'Nr04@  
85Hb~|0  
@+3@Z?!SZ  
public TestMethod() ,%FBELqOW  
{ ///xx/weblogic60b2_win.exe ]^63n/Twj  
try{ c8'! >#$  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); D6KYkN(,v  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =h4* ^NJ  
SiteFileFetch fileFetch = new SiteFileFetch(bean); BWbM$@'x  
fileFetch.start(); )aOPR|+  
} b@yGa%Gz@  
catch(Exception e){e.printStackTrace ();} MU; L7^  
'7!b#if  
8p?Fql}F [  
} |G5Me  
p)$DpNL% p  
yX:*TK4  
public static void main(String[] args) YmS}*>oz  
{ J1?)z+t9~  
new TestMethod(); W+&w'~M  
} q@i,$R  
} d8|bO#a%9  
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