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http断点续传简单实现(java)

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/* %uua_&#)  
**SiteFileFetch.java x df?nt  
*/ "ct58Y@   
package NetFox; QhsVIta  
import java.io.*; 3 &Sp@,  
import java.net.*; S_$nCyaH2  
Wa<-AZnh  
%P;[fJ `G  
public class SiteFileFetch extends Thread { ;5N41_hG  
jccOsG9;_  
6P^hN%0  
SiteInfoBean siteInfoBean = null; //文件信息Bean q=+ wI"[  
long[] nStartPos; //开始位置 'mJ13  
long[] nEndPos; //结束位置 k/@Tr :  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 oBC]UL;8xJ  
long nFileLength; //文件长度 `|,Bm|~:  
boolean bFirst = true; //是否第一次取文件 9>;} /*:H  
boolean bStop = false; //停止标志 7VY8CcL  
File tmpFile; //文件下载的临时信息 Fo(y7$33*  
DataOutputStream output; //输出到文件的输出流 6<PW./rk:  
` jyKCm.$#  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) { m'AY)  
public SiteFileFetch(SiteInfoBean bean) throws IOException vzG ABP  
{ ;Gh>44UM[  
siteInfoBean = bean; J 3B`Krh  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); {!r#f(?uT  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ;?`@"YG)  
if(tmpFile.exists ()) C5MqwNX  
{ *E7R(#,yC  
bFirst = false; fK"iF@=Z`  
read_nPos(); c$A@T~$  
} kP?_kMOx  
else {mf.!Xev  
{ 7D9]R#-K  
nStartPos = new long[bean.getNSplitter()]; V)h y0_  
nEndPos = new long[bean.getNSplitter()]; #Wk5E2t  
} QtlT&|$   
Why"G1`  
+q-c 8z  
(l_:XG)7~b  
} OpUA{P  
$ 9=8@  
yquAr$L!  
public void run() aj v}JV&:  
{ \4QH/e  
//获得文件长度 U(Z!J6{c  
//分割文件 y!5:dvt  
//实例FileSplitterFetch N iISJWk6'  
//启动FileSplitterFetch线程 &mdB\Y?^  
//等待子线程返回 NWaO_sm  
try{ HU9p !I.  
if(bFirst) ~1ps7[  
{ HzEGq,.  
nFileLength = getFileSize(); nALnB1  
if(nFileLength == -1) LuL$v+`  
{ {G%3*=?,j  
System.err.println("File Length is not known!"); O4!9{  
} ll2Vk*xs  
else if(nFileLength == -2) h1c{?xH2r  
{ dQK`sLChv  
System.err.println("File is not access!"); X|Dpt2A=  
} 8JP6M!F#  
else H0+:XF\M  
{ lvPpCAXY  
for(int i=0;i<nStartPos.length;i++) OEI3eizgH  
{ +(y>qd  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 6%UY1Q.?  
} Vmtzig3w[  
for(int i=0;i<nEndPos.length-1;i++) vzcz<i )  
{ J?,?fqb  
nEndPos = nStartPos[i+1]; cd+^=esSO  
} ;:?*t{r4#  
nEndPos[nEndPos.length-1] = nFileLength; AA2ui%  
} Z'e\_C  
} cyBW0wV1  
g<\>; }e  
w?S8@|MK  
//启动子线程 | @ *3^'  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; K-6p'|  
for(int i=0;i<nStartPos.length;i++) +dM.-wW  
{ 71*>L}H  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PF6 7z]<o  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), v4C3uNW  
nStartPos,nEndPos,i); ee^4KKsh\  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jr:drzr{I  
fileSplitterFetch.start(); |eF.ZC)QWh  
} ,H@TYw  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), b*`fLrqV.  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); CC>($k"  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", L&QtHSzy  
nEndPos = " + nFileLength); Q K j1yG0i  
// fileSplitterFetch[nPos.length-1].start(); $bFgsy*N2  
#<UuI9  
AoIc9E lEX  
//等待子线程结束 u]0!|Jd0  
//int count = 0; zu<>"5}]  
//是否结束while循环 :v#8O~  
boolean breakWhile = false; ey*,StT5a  
2]3G1idB  
;M-,HK4=  
while(!bStop) j C9<hLt  
{ %]!?{U\*k  
write_nPos(); ExQ--!AC=  
Utility.sleep(500); w~]} acP  
breakWhile = true; @BXaA0F4  
kR_E6Fl  
v=>3"!*  
for(int i=0;i<nStartPos.length;i++) R@&?i=gk  
{ GajI\_o  
if(!fileSplitterFetch.bDownOver) ah>Dqb*  
{ =^by0E2  
breakWhile = false; eiOi3q  
break; /CbkqNV  
} sv@}x[L  
} X!m;uJZp  
if(breakWhile) F\:{}782u  
break; m8p4U-*j  
P^ by'b+zI  
bnIf}ut-G  
//count++; 7;~ 2e  
//if(count>4) (Y&R0jt  
// siteStop(); UX?X]ZYVR  
} ^g\h]RD}  
\#HL`R"  
f7 K8m|  
System.err.println("文件下载结束!"); Y/#:)(&@  
} :LG}yq^  
catch(Exception e){e.printStackTrace ();} g}^4^88=a  
} MV7}  
#xDDh`  
A=y24m  
//获得文件长度 *'s&/vEy  
public long getFileSize() Z5 w`-#  
{ ^o,y5 ,  
int nFileLength = -1; <ihhV e  
try{ |P^ikx6f5  
URL url = new URL(siteInfoBean.getSSiteURL()); /%c+ eL}l  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `>$g y/N  
httpConnection.setRequestProperty("User-Agent","NetFox"); ^Jc$BMaVg  
W5 M ]  
_Jt_2o%G  
int responseCode=httpConnection.getResponseCode(); Z{Lmd`<w`j  
if(responseCode>=400) ,%& LG],6  
{ }S1Z>ZA5  
processErrorCode(responseCode); _gis+f/8h  
return -2; //-2 represent access is error +F#=`+V  
} bL6L-S  
RI7qsm6RN  
bgkbwE  
String sHeader; ? Yynd  
^d5gz0d  
.N'%hh  
for(int i=1;;i++) T9&,v<f  
{ h Kp,4D>2_  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); yHV^a0e7EH  
//Utility.log(in.readLine()); `Pz!SJ|  
sHeader=httpConnection.getHeaderFieldKey(i); .2 N_?  
if(sHeader!=null) !07FsPI#{  
{ N> uZt2  
if(sHeader.equals("Content-Length")) HXl r  
{ A,-[/Z K/  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); bqf]$}/8k  
break; V{/)RZ/  
} fS8XuT  
} qkZ5+2m  
else ,Yiq$Z{qQ  
break; Gx~"iM  
} *IjdN,wox  
} Ynk><0g6  
catch(IOException e){e.printStackTrace ();} dd @COP?  
catch(Exception e){e.printStackTrace ();} W}<M?b4tP  
Xm0&U?dZB  
Zip K;!9by  
Utility.log(nFileLength); [|m>vY!  
|{}d5Z"5;}  
}(vOaD|k=  
return nFileLength;  5Fl  
} :*w:eKk  
7kWZMi  
#7cf 8y  
//保存下载信息(文件指针位置) Xoa <r9  
private void write_nPos() JXI+k.fi  
{ $HR(|{piZ  
try{ Nsy9 h}+A  
output = new DataOutputStream(new FileOutputStream(tmpFile)); w$<fSe7  
output.writeInt(nStartPos.length); <|>:UGAR  
for(int i=0;i<nStartPos.length;i++) =O}%bZ)Q  
{ R;Ix<y{U  
// output.writeLong(nPos); C>(M+qXL+  
output.writeLong(fileSplitterFetch.nStartPos); q}7Df!<|  
output.writeLong(fileSplitterFetch.nEndPos); {H7$uiq3:B  
} Z:o' +oh  
output.close(); Af! W K=  
} 7+2aG  
catch(IOException e){e.printStackTrace ();} bju,p"J1-E  
catch(Exception e){e.printStackTrace ();} +XaO?F[c  
} XH Zu>[  
1H2u,{O  
:8GxcqvCWq  
//读取保存的下载信息(文件指针位置) ju2X*  
private void read_nPos() N4GIb 6  
{ 3Jk?)D y  
try{ y[7xK}`_  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /\Y%DpG$  
int nCount = input.readInt(); 4@V<Suw  
nStartPos = new long[nCount]; !?>p]0*<  
nEndPos = new long[nCount]; v.8S V]  
for(int i=0;i<nStartPos.length;i++) c K}  
{ T;pn -  
nStartPos = input.readLong(); J;]@?(  
nEndPos = input.readLong(); 9QM"JEu@  
} -r2qIt  
input.close(); 8@C|exAD`  
} 5<GRi "7A@  
catch(IOException e){e.printStackTrace ();} ,9j:h)ks?  
catch(Exception e){e.printStackTrace ();} W&re;?Z{ke  
} 9,a,A6xry  
Y Z2VP  
1Qe!  
private void processErrorCode(int nErrorCode) Cot\i\]jv  
{ L" ^366M!  
System.err.println("Error Code : " + nErrorCode); 36Y[7 m=  
} r#Oz0=0u  
)aA9z(x  
EF^=3  
//停止文件下载 7;-i_&vws  
public void siteStop() 9TN5|x  
{ -/{}^ QWB  
bStop = true; WsDe0F  
for(int i=0;i<nStartPos.length;i++) =X'7V}Q}  
fileSplitterFetch.splitterStop(); M[N.H9  
M4PUJZ]  
r{jD,x2  
} <%JO 3E  
} L;t~rW!1  
//负责部分文件的抓取 "LaX_0t)  
**FileSplitterFetch.java 29DWRJU  
*/ [MP :Eeg  
package NetFox; ? Z fhz   
7Cp_ 41._  
cW^) $>A  
import java.io.*; &bgi0)>  
import java.net.*; _%%"Y}  
t"vO&+x  
:R\v# )C  
public class FileSplitterFetch extends Thread { yzl\{I&  
,T[ +omo  
/\I%)B47^9  
String sURL; //File URL 1Sk6[h'CL  
long nStartPos; //File Snippet Start Position M:f=JuAx  
long nEndPos; //File Snippet End Position ?Gw89r  
int nThreadID; //Thread's ID ,w>?N\w!}  
boolean bDownOver = false; //Downing is over cHct|Z u  
boolean bStop = false; //Stop identical .g?,:$`0D?  
FileAccessI fileAccessI = null; //File Access interface xmx;tq  
Sylsp%A  
o^6j(~  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?tQv|x  
{ >g2.z>  
this.sURL = sURL; Pk_{{Z(1o  
this.nStartPos = nStart; V3UGx'@^y  
this.nEndPos = nEnd; HNT8~s.2  
nThreadID = id; DK%eFCo<~  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 zD-8#H35X"  
} R?SHXJ%'  
X+@,vCC  
E=trJge  
public void run() EBLoRW=8ld  
{ r!iuwE@  
while(nStartPos < nEndPos && !bStop) tpK4 gjf  
{ m/Z_HER^  
XS/TYdXB8  
"r+<=JU>OV  
try{ !{;RtUPz*  
URL url = new URL(sURL); Ts6X:D4,  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :nEV/"#F  
httpConnection.setRequestProperty("User-Agent","NetFox"); ro@BmRMW  
String sProperty = "bytes="+nStartPos+"-"; &nP rozC  
httpConnection.setRequestProperty("RANGE",sProperty); .5xg;Qg\Y  
Utility.log(sProperty); jp`N%O]6  
ic#drpl,  
VRt*!v<")  
InputStream input = httpConnection.getInputStream(); rgY~8PY"  
//logResponseHead(httpConnection); Wz]S+IpY  
{%Sw w:  
%-CC_R|0$  
byte[] b = new byte[1024]; pnU g:R@  
int nRead; Y~xZ{am  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,L G&sa"  
{ H_FhHX.2(  
nStartPos += fileAccessI.write(b,0,nRead); _T$\$v$ {  
//if(nThreadID == 1) 'CX KphlWs  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qT4s* kqr  
} U_No/$ b  
qfU3Cwy  
aJ5R0Y,  
Utility.log("Thread " + nThreadID + " is over!"); E.9F~&DPJ<  
bDownOver = true; _?ZT[t<  
//nPos = fileAccessI.write (b,0,nRead); :*1w;>o)n  
} T2{+fR v N  
catch(Exception e){e.printStackTrace ();} '\Ub*m((1O  
} 4SYN$?.Mp  
} 51vK>  
./d (@@  
EIRf6jL  
//打印回应的头信息 Gf?KpU  
public void logResponseHead(HttpURLConnection con) LHb{9x  
{ x-<dJ}`  
for(int i=1;;i++) ; F=_ozWV*  
{ j4h 7q<  
String header=con.getHeaderFieldKey(i); _*9Zp1r  
if(header!=null) Gu= Rf`o  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 7}Sw(g)o7  
Utility.log(header+" : "+con.getHeaderField(header)); =%L^!//c  
else 9O"?T7i"#  
break; C N"c  
} }/VHeHd  
} R|suBF3  
fHigLL0B  
-n9e-0  
public void splitterStop() fp7Qb $-A  
{ }=U\v'%m  
bStop = true; 1}6pq 2  
} p,Z6/e[SI  
0e7!_ /9  
4g 1h:I/  
} C$bK!]a  
$?\],T  
x\jHk}Buj  
/* 7v-C-u[E`  
**FileAccess.java *M"wH_cd  
*//文件访问(定位,写) <n>< A+D  
package NetFox; MiC&av  
import java.io.*; ?o4&cCFOE  
& zG=  
m[}$&i$(  
public class FileAccessI implements Serializable{ 4=9F1[  
te|VKYN%}[  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `drvu?F  
RandomAccessFile oSavedFile; @.})nU  
long nPos; ESO(~X+  
OD i)#  
D,hl+P{^K  
public FileAccessI() throws IOException %$cwbh-{{  
{ b,c vQD  
this("",0); 78X;ZMY  
} >$?Z&7Lv  
4uz\Me(  
v}!,4,]:&  
public FileAccessI(String sName,long nPos) throws IOException {*|yU"  
{ F :u}7t>  
oSavedFile = new RandomAccessFile(sName,"rw"); &~k/G  
this.nPos = nPos; D\k);BU~  
oSavedFile.seek(nPos); #*9*[Xbi  
} X)yTx8v4  
i->sw#  
,^+3AT  
public synchronized int write(byte[] b,int nStart,int nLen)  E5o0^^  
{ #&@&BlIe  
int n = -1; 8^^al!0K~  
try{ nK:39D$(  
oSavedFile.write(b,nStart,nLen); aqMZ%~7  
n = nLen; _|*j8v3  
} ^iGIF~J9  
catch(IOException e) @<};Bo'  
{ P$!Ht  
e.printStackTrace ();  V C.r  
} 5Zq- |"|  
r}vr E ^Q  
M0^r!f>O  
return n; *kDXx&7B$  
} [0 W^|=#K  
XL +kEZ|3  
t$}+oCnkv  
} .M_;mhRI  
'- Z4GcL  
08'JT{iid  
/* lRO4- y  
**SiteInfoBean.java OyH:  
*/ h IGa);g  
package NetFox; 9 /9,[A  
R+^/(Ws'<  
Uqkh@-6-  
public class SiteInfoBean { 4ba1c  
!{SEm"J^  
MY0Wr%@#0  
private String sSiteURL; //Site's URL B$7lL  
private String sFilePath; //Saved File's Path Wve ^2lkoK  
private String sFileName; //Saved File's Name 6R?J.&|  
private int nSplitter; //Count of Splited Downloading File 4=1lyw  
w| >Y&/IX  
-,Q<*)q{  
public SiteInfoBean() |R+=Yk&u  
{//nSplitter的缺省值为5 eNXpRvY  
//default value of nSplitter is 5 YrB-;R 1+  
this("","","",5); M>0~Ek%3  
} RRV&!<l@$  
dso\+s  
/0(4wZe~?  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) S_\RQB\l  
{ 4h(aTbHaQ  
sSiteURL= sURL; J H$  
sFilePath = sPath; #ReW#?P%b/  
sFileName = sName; ~>{<r{H"S  
this.nSplitter = nSpiltter; \Ud2]^D=  
+[z(N  
{Q4=GrS  
} dAga(<K  
==IL63  
C8(sH@  
public String getSSiteURL() y*zZ }>  
{ 0{Tf;a<  
return sSiteURL; FmnA+fA  
} {5*+  
Z3[,Xw  
I</Nmgf  
public void setSSiteURL(String value) x %$Z/  
{ ,kLeK{   
sSiteURL = value; ]QpR>b=[j  
} 5nEvnnx0  
hI/p9 `w  
,(lD5iN  
public String getSFilePath() Xf#uK\f  
{ .p0;y3so4  
return sFilePath; sba0Q[IY  
} -[+FVvS  
$|A vT;4  
Ph-3,cC  
public void setSFilePath(String value) CuDU~)`  
{ 1OJ:Vy}n  
sFilePath = value; :%s9<g;-h_  
} 6`EyzB%.$  
b}[{'  
mz/KGZ5t  
public String getSFileName() hWuq  
{ J&h 3,  
return sFileName; ZP?](RV>xg  
} W6]iJ  
:Rq@%rL  
4?8GK  
public void setSFileName(String value) DfqXw^BKD  
{ 8vnU!r  
sFileName = value; sd>#Hn  
} R'&^)_  
<sd Qvlx$-  
8CMI\yk  
public int getNSplitter() =g?r.;OO  
{ o1YhYA  
return nSplitter; l1!i3m'x  
} Br-bUoua  
vE{QN<6T  
JQI`9$asuC  
public void setNSplitter(int nCount) <w08p*?  
{ T,jxIFrF  
nSplitter = nCount; 0wxQ,PI1'  
} "PnYa)?1  
} c1b@3  
+X.iJ$)  
r+\it&cW+  
/* H2rh$2  
**Utility.java (9'MdH  
*/ 7Nx@eoZ  
package NetFox; *}3~8fu{  
>>K) 4HYID  
D[yaAG<  
public class Utility { kU4Zij-O  
c]&(h L  
oM QH- \(}  
public Utility() 0jE,=<W0>  
{ 7| IW\  
>0B [  
}?8KFe7U  
} $ 'HiNP {c  
;%Jp@'46  
//线程睡眠 ;/ >~|@  
public static void sleep(int nSecond) AaKILIIQZ  
{ />)>~_-3  
try{ Y"G$^3% (]  
Thread.sleep(nSecond); rDm>Rm=  
} ~r&Q\G  
catch(Exception e) Cg8{NNeD  
{ 7A7K:,c  
e.printStackTrace (); \ >1M?  
} Y==# yNwM  
} '^lrGO6 z7  
0Rrz   
//日志 V ;"?='vVe  
public static void log(String sMsg) OjyS ?YY)b  
{ GsE?<3  
System.err.println(sMsg); q>!T*BQ  
} B_c(3n-"  
(;C_>EL&u  
$(#o)r>_R  
public static void log(int sMsg) K#+TCZ,  
{ LP#CA^*S  
System.err.println(sMsg); Y13IrCA2  
} G@ed2T  
} :8yrtbf$  
I`DdhMi7  
+- c#UO>  
/* qt/"$6]%  
**TestMethod.java <$,i Yx   
*/ 8t9sdqM/C  
package NetFox; \`|,wLgH  
&hjrJ/'^  
~sMn/T*fv  
public class TestMethod { VO. Y\8/  
Ya304Pjd  
DCP "  
public TestMethod() hFylQfd  
{ ///xx/weblogic60b2_win.exe "R4~ 8r  
try{ $N:m 9R  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); d=N5cCqq  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); u&2uQ-T0  
SiteFileFetch fileFetch = new SiteFileFetch(bean); [C P V5\2  
fileFetch.start(); =xai 7iM  
} U>ob)-tl  
catch(Exception e){e.printStackTrace ();} \muyL?  
>d#B149  
;( VJZ_  
} ]+d.X]   
^Q2K0'm5  
?HZ+fS ,-  
public static void main(String[] args) :%!=Ej.J  
{ )k0bP1oGS  
new TestMethod(); /HI#8  
} Ca?pK_Y  
} AO>K 6{  
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