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http断点续传简单实现(java)

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/* UFu0{rY_  
**SiteFileFetch.java 7U?#Xi5  
*/ *j,bI Y&se  
package NetFox; hc3tzB  
import java.io.*; ZI1*Cb  
import java.net.*; <mj/P|P@  
sINf/mv+  
u;!h   
public class SiteFileFetch extends Thread { OU}eTc(FeC  
>B=s+ }/ME  
#sBL E  
SiteInfoBean siteInfoBean = null; //文件信息Bean mBb3Ta  
long[] nStartPos; //开始位置 H1L)9oa  
long[] nEndPos; //结束位置 B3D}'<  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 t&F:C  
long nFileLength; //文件长度 mEu2@3^E }  
boolean bFirst = true; //是否第一次取文件  o0>|  
boolean bStop = false; //停止标志 (6NDY5h~=n  
File tmpFile; //文件下载的临时信息 </@5>hx/  
DataOutputStream output; //输出到文件的输出流 ~d1=_p:~T  
i+_=7(e  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) =:xX~,qmv  
public SiteFileFetch(SiteInfoBean bean) throws IOException LI25VDZ|iP  
{ ,4`Vl<6  
siteInfoBean = bean; 4nP4F +  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); b 9"t%R9/Q  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); WT")tjVKA  
if(tmpFile.exists ()) a5saN5)H  
{ lJ]QAO  
bFirst = false; F$jy~W_  
read_nPos(); 5uahfJk  
} I)vR  
else K3`!0(  
{ SZLugyZ2Y  
nStartPos = new long[bean.getNSplitter()]; Y\WVkd(+G  
nEndPos = new long[bean.getNSplitter()]; zPybP E8  
} `OgT"FdL!  
!Q_Wbu\U  
Ejr'Yzl3_  
QV HI}3~  
} tU2#Z=a  
]!P8{xmb@  
` - P1Y  
public void run() J$5 G8<d>  
{ }CMGK{  
//获得文件长度 ~@ PD\  
//分割文件 = M4:nt  
//实例FileSplitterFetch E`(=n(Qu  
//启动FileSplitterFetch线程 8Dtpb7\o  
//等待子线程返回 (n: A` ]  
try{ &4}=@'G@  
if(bFirst) WQ8 "Jj?k6  
{ Vp~ cN  
nFileLength = getFileSize(); ~|Ln9f-g  
if(nFileLength == -1) cF=WhP*f  
{ (3D&GY!/  
System.err.println("File Length is not known!"); <-b9 )>  
} m a@V>*u  
else if(nFileLength == -2) %,z;W-#gnY  
{ mVYfyLZ,(  
System.err.println("File is not access!"); Y/I)ECm  
} 1 hFh F^  
else 4ytdcb   
{ na8`V`77  
for(int i=0;i<nStartPos.length;i++) EmrkaV-?k  
{ hgW1g#  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); GH-Fqz  
} "+7E9m6I  
for(int i=0;i<nEndPos.length-1;i++) N\Lu+ x5  
{ Ug546Bz  
nEndPos = nStartPos[i+1]; pg7~%E4  
} /FC HF#yK  
nEndPos[nEndPos.length-1] = nFileLength; jVN06,3z  
} 3<M yb  
} ?<W|Ya  
>K4Nn(~ys  
+y'2 h%>h[  
//启动子线程 oOvQA W8`  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %Gyn.9\  
for(int i=0;i<nStartPos.length;i++) $H)!h^7^9  
{ :2==7u7v?  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .uS`RS8JM  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0(f+a_2^Q  
nStartPos,nEndPos,i); =fnBE`Uc  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); n~\; +U  
fileSplitterFetch.start(); uHZ4 @ w:  
} S#8)N`  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), wf]?:'}  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1|xe'w{  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]*mUc`  
nEndPos = " + nFileLength); @M-w8!.~  
// fileSplitterFetch[nPos.length-1].start(); R?:Q=7K  
F_R\  
xl,% Z~[  
//等待子线程结束 lGR0-Gh2  
//int count = 0; 612,J  
//是否结束while循环 K`9~#Zx$  
boolean breakWhile = false; Q"{Dijc%  
 cf,6";8  
.|go$}Fk  
while(!bStop) #'> )?]tn  
{ ?uL-qsU  
write_nPos(); xcmg3:s  
Utility.sleep(500); Wj|W B*B  
breakWhile = true; ZpOME@9,  
_,(s  
(T pnJq  
for(int i=0;i<nStartPos.length;i++) RDHK'PGA  
{ %Y;^$%X%_  
if(!fileSplitterFetch.bDownOver) [@VzpVhXz  
{ M_%KhK  
breakWhile = false; _wb]tE ~g  
break; +8?18@obp  
} j[dZ*Jr_  
} FqbGT(QB0  
if(breakWhile) 5&EBU l}  
break; 6AY( /N8V  
Pi?G:IF  
5;/q[oXI  
//count++; 1I69O6"  
//if(count>4) ETU-6qFtO  
// siteStop(); J>T98y/))  
} 'bM=  
viYrPhH+z  
2Ul8<${c{  
System.err.println("文件下载结束!"); 9<3}zwJ  
} IZ>l  
catch(Exception e){e.printStackTrace ();} r7_%t_O|IL  
} :'<;]~f  
"DvZCf[}  
L#a!fd  
//获得文件长度 <h#W*a  
public long getFileSize() gS[B;+d  
{ = )3\B  
int nFileLength = -1; Gq[5H(0/c  
try{ ,Il) tH  
URL url = new URL(siteInfoBean.getSSiteURL()); EMr|#}]#s  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d\3 %5Y  
httpConnection.setRequestProperty("User-Agent","NetFox"); (:E@kpK  
xqg4b{  
T&6>Eb0{  
int responseCode=httpConnection.getResponseCode(); kzCJs  
if(responseCode>=400) \/ri|fm6l#  
{ ~V?z!3r-)  
processErrorCode(responseCode); @.k^ 8hc  
return -2; //-2 represent access is error > fV "bj.  
} Q -$) H;,  
rt*>)GI]b  
#=)>,6Z w  
String sHeader; "S'Yn-  
v]Pyz<+  
tXrKC  
for(int i=1;;i++) |/xA5_-N  
{ w]h8KNt  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); havmhS)O  
//Utility.log(in.readLine()); l-c:'n  
sHeader=httpConnection.getHeaderFieldKey(i); abS~'r14  
if(sHeader!=null) y?r`[{L(lA  
{ ~$^ >Vo  
if(sHeader.equals("Content-Length")) T ?A3f]U  
{ OUwnVAZZ6  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); e#}Fm;|d  
break; ^uw]/H3?L  
} HWFTI /]  
} J_yXL7d  
else pd,d"+  
break; Hq>hnCT  
} UB>BVBCt  
} s}UJv\*  
catch(IOException e){e.printStackTrace ();} +CSv@ />3  
catch(Exception e){e.printStackTrace ();} JP( tf+  
^@=4HtA  
DS@Yto  
Utility.log(nFileLength); tG9C(D`G  
1Lje.%(E.  
0cfGI%  
return nFileLength; 6q`)%"4k  
} Cq<Lj  
.dxELSV  
#k &#d9}  
//保存下载信息(文件指针位置) G9j f]Ye;  
private void write_nPos() !or_CJ8%  
{ {=&( { cS  
try{ sL\ {.ad5  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2$t%2>1>@  
output.writeInt(nStartPos.length); @\oZ2sB  
for(int i=0;i<nStartPos.length;i++) mv,a>Cvs[  
{ [%6)  
// output.writeLong(nPos); ?5};ONjN  
output.writeLong(fileSplitterFetch.nStartPos); Tu}EAr  
output.writeLong(fileSplitterFetch.nEndPos); M5:*aCN6P  
} ,|z zq@fk  
output.close(); <RC%<  
} CsT&}-C  
catch(IOException e){e.printStackTrace ();} w<]-~`K  
catch(Exception e){e.printStackTrace ();} <ycR/X  
} ;iJxJX\+  
OfA+|xT&  
`Z{s,!z  
//读取保存的下载信息(文件指针位置) q;sZwp<  
private void read_nPos() C+`V?rp=s  
{ >X iT[Ru  
try{ &AeNrtGu  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /yx)_x{  
int nCount = input.readInt(); qJonzFp7  
nStartPos = new long[nCount]; /<+`4n  
nEndPos = new long[nCount]; 4 eSFpy1  
for(int i=0;i<nStartPos.length;i++) cud9oJ-=;  
{ =^{MyR7  
nStartPos = input.readLong(); 1#+|RL4o  
nEndPos = input.readLong(); F)imeu  
} @;hdZLG]`&  
input.close(); L5|g \Y`  
} cmCD}Skk  
catch(IOException e){e.printStackTrace ();} T9kc(i'  
catch(Exception e){e.printStackTrace ();} s0x/2z  
} 6 A#xFPYY{  
1Q9Hs(s  
bBo>Y7%  
private void processErrorCode(int nErrorCode) w"QZ7EyJ  
{ 5~2_wWjX  
System.err.println("Error Code : " + nErrorCode); S^EAE]  
} BE~-0g$W  
K@Q%NK,  
Z8Vof~  
//停止文件下载 C#)T$wl[E  
public void siteStop() JxLfDr,dy  
{ <X& fs*x&  
bStop = true; nf&5oE^  
for(int i=0;i<nStartPos.length;i++) /PR 4ILed  
fileSplitterFetch.splitterStop(); Y"s8j=1m  
E GZiWBr  
$bZ-b1{c C  
} #&L7FBJ"*v  
} Z6Kp-z(l3  
//负责部分文件的抓取 \M0's&1(  
**FileSplitterFetch.java A9"!=/~  
*/ 7kT X  
package NetFox; `GCK%evLG  
hJk:&!M=T  
]Ge>S?u  
import java.io.*; UVgSO|Tg  
import java.net.*; 0,.|-OZ  
&uBf sa$  
Bm%|WQK  
public class FileSplitterFetch extends Thread { +StsSZ  
l]&x~K}  
[*0M$4  
String sURL; //File URL H/;AlN|!  
long nStartPos; //File Snippet Start Position EdSUBoWF}  
long nEndPos; //File Snippet End Position fZ;}_wR-H  
int nThreadID; //Thread's ID |Sua4~yL(  
boolean bDownOver = false; //Downing is over MLmaA3  
boolean bStop = false; //Stop identical elpTak@  
FileAccessI fileAccessI = null; //File Access interface 1~LfR  
DUF$-'A  
BS?$eai@:9  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException C=cn .CX  
{ ~82 {Y _{/  
this.sURL = sURL; $% gz, {  
this.nStartPos = nStart; 7^LCP*  
this.nEndPos = nEnd; :$PrlE  
nThreadID = id; +o"CMI  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "5sA&^_#_  
} ?cKTeGrS  
Z 5)v  
Ck"db30.  
public void run() Cx.##n0  
{ VEn3b  
while(nStartPos < nEndPos && !bStop) T0)bnjm  
{ k%kEW%I yG  
de.f?y  
LXhR"PWZM\  
try{ p|dn&<kd  
URL url = new URL(sURL); H=g%>W%3  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #Er"i  
httpConnection.setRequestProperty("User-Agent","NetFox"); Q6e7Z-8  
String sProperty = "bytes="+nStartPos+"-"; eO*s,*  
httpConnection.setRequestProperty("RANGE",sProperty); 6%>'n?  
Utility.log(sProperty); F[!%,-*  
M5t.l (  
T:H~Y+qnt  
InputStream input = httpConnection.getInputStream(); Iw h0PfWJ  
//logResponseHead(httpConnection); j|N<6GSke  
) jvI Nb  
M*Ej*#  
byte[] b = new byte[1024]; [?O4l`  
int nRead; 5 ;XYF0  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6-)WXJ@V  
{ (c^ {T)  
nStartPos += fileAccessI.write(b,0,nRead); 6akI5\b  
//if(nThreadID == 1) b09xf"D  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ',t*:GBZCf  
} d,Oagx  
K9p<PLy+  
]j6K3  
Utility.log("Thread " + nThreadID + " is over!"); }HmkTk  
bDownOver = true; CmBgay  
//nPos = fileAccessI.write (b,0,nRead); O"\_%=X9  
} M"/Jn[  
catch(Exception e){e.printStackTrace ();} : xggo  
} ju "?b2f  
} rBi<Yy$z  
-o`K/f}d  
G kG#+C0L  
//打印回应的头信息 5$HG#2"Kb#  
public void logResponseHead(HttpURLConnection con) d^!k{Qx'  
{ f5b|,JJ  
for(int i=1;;i++) U1E@pDH  
{ ?*+U[*M  
String header=con.getHeaderFieldKey(i); SOM? 0.  
if(header!=null) :l!sKT?:d!  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); z 5(5\j]  
Utility.log(header+" : "+con.getHeaderField(header)); yI#qkl-  
else GA[D@Wy  
break; hif;atO  
} . _|=Btoo  
} V;"2=)X  
Cb?  !+U  
"RK"Pn+  
public void splitterStop() 3Wbd=^hRvq  
{ A:GqR;;"x>  
bStop = true; A46q`l9B  
} :/szA?:W  
 R.HvqO  
RH _b  
} O TlqJ  
%N ~c9B  
p}1gac_c  
/* Tgtym"=xd  
**FileAccess.java Y,Z$U| U  
*//文件访问(定位,写) 5YNAb/! !F  
package NetFox; #-G@p  
import java.io.*; :.XlAQR~b  
2#lpIj  
y'odn ;  
public class FileAccessI implements Serializable{ gL&w:_  
CkNR{?S  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 fg#e*7Odn  
RandomAccessFile oSavedFile;  ArAe=m!u  
long nPos; JkT!X  
:'C?uk ?  
qg`ae  
public FileAccessI() throws IOException f&^}yqmuE  
{ TsoxS/MI"  
this("",0); .$x}~Sw  
} BV>9U5  
*k,3@_5  
a BMV6'  
public FileAccessI(String sName,long nPos) throws IOException ),B/NZ/-  
{ ri59LYy=  
oSavedFile = new RandomAccessFile(sName,"rw"); u;rmqo1  
this.nPos = nPos; (n?f016*%d  
oSavedFile.seek(nPos); 8gE p5  
} fcF|m5  
exiu;\+j  
r^C(|Vx  
public synchronized int write(byte[] b,int nStart,int nLen) 8YRT0/V  
{ >\pF5a`  
int n = -1; W? 4:sLC#3  
try{ 5ILKYUg,  
oSavedFile.write(b,nStart,nLen); 3-:^mRPJ  
n = nLen; Ar/P%$Zfq  
} Y1sK sdV  
catch(IOException e) vW*Mf}=  
{ oi7k#^  
e.printStackTrace (); #BBDI  
} k}<H  
.@nfqv7{  
RbxQTM_:M  
return n; j1{`}\e  
} 0.R3(O  
|-\anby<  
Y)]VlV!`  
} iExKi1knx  
6<S-o|Xw  
y,&[OrCm^\  
/* -wC}JVVcK  
**SiteInfoBean.java !L9|iC:8  
*/ By7lSbj  
package NetFox; ~s'}_5;VY  
Rh"O$K~  
l{8O'4;  
public class SiteInfoBean { [|*7"Q(  
) aMiT  
*(r9c(xa  
private String sSiteURL; //Site's URL $0$sDN6)x  
private String sFilePath; //Saved File's Path \^y~w~g?  
private String sFileName; //Saved File's Name 7#UJ444b~  
private int nSplitter; //Count of Splited Downloading File sxF2ku4A  
6 A]a@,PC  
k3B_M9>!  
public SiteInfoBean() *zweZG8:  
{//nSplitter的缺省值为5 /K!f3o+  
//default value of nSplitter is 5 5 8;OTDR!  
this("","","",5); F)eP55C6  
} Oz(=%oS  
'M?ptu?f  
z)*{bz]  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~0-)S@  
{ o(54 A['  
sSiteURL= sURL; .HY,'oC.  
sFilePath = sPath; X04LAYY_u  
sFileName = sName; GcO:!b*YMp  
this.nSplitter = nSpiltter; e&ZTRgYdi  
8_`C&vx  
K`X'Hg#_P2  
} 94 6r#`q  
ON!Fk:-  
,s}&|+ '"  
public String getSSiteURL() Snmv  
{ ;IPk+,hpmi  
return sSiteURL; Xs$a^zZ  
} 751Q i  
wS7Vo{#@\  
^zqQ8{oV  
public void setSSiteURL(String value) 8VG~n?y  
{ DTi^* Wj  
sSiteURL = value; CUC]-]8  
} O<>+l*bk  
 rB(Q)N  
4UW)XLu6T7  
public String getSFilePath() dn=srbJ   
{ 4C:dkaDq]  
return sFilePath; 3ErV" R4"$  
} d=vD Pf  
Z5wQhhH  
@sd{V  
public void setSFilePath(String value) D"fjk1  
{ gLo&~|=L-  
sFilePath = value;  ++8 Xi1  
} l_2l/ff9  
i8EKzW  
p ~+sk1[.  
public String getSFileName() kwS[,Qy\  
{ Bv*VNfUm  
return sFileName; }VH2G94Ll  
} wc}x [cS  
RJT55Rv{  
V0#E7u`4  
public void setSFileName(String value) 0}k vuuR  
{ vj#m#1\ f  
sFileName = value; 3XbFg%8YG  
} !+ UXu]kA  
!([v=O#  
%md9ou`  
public int getNSplitter() &Dp&  
{ rg%m   
return nSplitter; rX`fjS*C  
} 'P&r^V\~(/  
W^H[rX}=  
#fyY37-  
public void setNSplitter(int nCount) 98{n6$\  
{ TUp%Cx  
nSplitter = nCount; {+9t!'   
} hNp.%XnnZ  
} ,~K4+ t_  
GsqO^SV  
yW"}%) d  
/* ,zBc-Cm  
**Utility.java ^M1O)   
*/ |ew:}e: k<  
package NetFox; )B5U0iIi  
P[ Vf$ q<  
}L5;=A']S  
public class Utility { =G rg  
vZSwX@0  
O=Vj*G ,  
public Utility() B8V85R  
{ 57U;\L;ZmZ  
Yd~Tzh  
&G+:t)|S  
} Fi+,omB&  
V}G; oz&>)  
//线程睡眠 00A2[gO9  
public static void sleep(int nSecond) C2J@]&  
{ Cz4l  
try{ Vao3 &#D8  
Thread.sleep(nSecond); JG'&anbm  
} 7I6& *I  
catch(Exception e) n yd'79~>G  
{ YW-Ge  
e.printStackTrace (); 5kj=Y]9\I  
} N8]d0  
} NVo =5  
}j#c#''i  
//日志 `q1K%id  
public static void log(String sMsg) _d3/="=  
{ &eX^ll  
System.err.println(sMsg); cU=EXyP%  
} zeHs5P8}r  
mINir-  
S 5nri(m  
public static void log(int sMsg) -M?s<R[&  
{ }Xy<F?Mh  
System.err.println(sMsg); j&=!F3[  
} ? $X1X`@  
} & Pzr)W(  
,O"zz7  
Y !nE65  
/* 0SWec7G  
**TestMethod.java z4c{W~}`  
*/ kA<58 ,!  
package NetFox; 'd=B{7k@  
C&KH.h/N  
mE_?E&T`|  
public class TestMethod { Y[ toN9,  
i!EN/Bd  
pD%Pg5p`  
public TestMethod() c27A)`   
{ ///xx/weblogic60b2_win.exe *4F6U  
try{ 8;]U:tv  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); E h>qUa  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); P_ x9:3  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8!{F6DG  
fileFetch.start(); 8DP] C9  
} x*uQBNf=  
catch(Exception e){e.printStackTrace ();} W-+~r  
#Y;_W;#  
&c)n\x*  
} `-L{J0xq  
oO8V0VE\  
2-*zevPiG=  
public static void main(String[] args) Y^-faL7*\  
{ UfnjhHu  
new TestMethod(); 9'|NF<  
} IirXF?&t  
} 9,`eYAu  
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