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http断点续传简单实现(java)

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/* }'TTtV:Q  
**SiteFileFetch.java l DnMjK\M  
*/ /~*Cp9F"]  
package NetFox; PPj[;(A  
import java.io.*; EI\v  
import java.net.*; HUkerV  
<raG07{!*  
~0ooRUWU7  
public class SiteFileFetch extends Thread { 5q Rc4d'  
y AOg\+  
(f~gEKcB2u  
SiteInfoBean siteInfoBean = null; //文件信息Bean XVF^,Yf  
long[] nStartPos; //开始位置 69/?7r  
long[] nEndPos; //结束位置 T(V8; !  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 (]XbPW  
long nFileLength; //文件长度 2e.N"eLNt  
boolean bFirst = true; //是否第一次取文件 # k9 <  
boolean bStop = false; //停止标志 8R}K?+]  
File tmpFile; //文件下载的临时信息 4uUs7T  
DataOutputStream output; //输出到文件的输出流 +T2HE\  
_q)!B,y-/N  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) l{5O5%\,  
public SiteFileFetch(SiteInfoBean bean) throws IOException @KA1"Wb_  
{ ` 8UWE {  
siteInfoBean = bean; 4LsHs   
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Qn.[{rw  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ue6d~8&  
if(tmpFile.exists ()) c 0-w6  
{ C(o.Cy6  
bFirst = false; Yj|]Uff8O  
read_nPos(); IqUp4}  
} `(DJs-xD  
else @Tr&`Hi  
{ ^.vmF>$+I  
nStartPos = new long[bean.getNSplitter()]; NR4Jn?l{  
nEndPos = new long[bean.getNSplitter()]; a4&:@`=  
} Jq .L:>x  
{155b0  
CCqT tp  
"- eZZEl(  
} xo  Gb  
-e ml  
-;pOh;WG  
public void run() ArzDI{1  
{ ZJ(rG((!  
//获得文件长度  AmcC:5  
//分割文件 (Z-l/)Q  
//实例FileSplitterFetch xU}M;4kH~  
//启动FileSplitterFetch线程 YH\j@ ^n  
//等待子线程返回 3.vgukkk5  
try{ vT7g<  
if(bFirst) MEq"}zrh  
{ B4yh3cf  
nFileLength = getFileSize(); T2weAk#J  
if(nFileLength == -1) i:Y\`J  
{ vM`~)rO@!  
System.err.println("File Length is not known!"); KDey(DN:  
} \[#t<dD  
else if(nFileLength == -2) ai;\@$ cq  
{ |!LnAh  
System.err.println("File is not access!"); rLF*DB3l  
} B~TN/sd  
else oT&m4I  
{ |J3NR`-R  
for(int i=0;i<nStartPos.length;i++) 'jvpNn  
{ q`Q}yE> 9  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 9.&mz}q  
} 7=k^M, a  
for(int i=0;i<nEndPos.length-1;i++) L"vj0@n'0  
{ c tI{^f:  
nEndPos = nStartPos[i+1]; B8V,)rn  
} qLjT.7 .x  
nEndPos[nEndPos.length-1] = nFileLength; WRpyr  
} `ZGcgO<c\  
} K)[8 H~Lm  
[e e30ELn  
#I%s 3  
//启动子线程 nPA@h  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q~Ea8UT. #  
for(int i=0;i<nStartPos.length;i++) #H5=a6E+q  
{ g`?:=G:a*  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V3.t;.@  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), g1|w?pI1  
nStartPos,nEndPos,i); CAgaEJhX3  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A';QuWdT  
fileSplitterFetch.start(); 213\ehhG<  
} %Q4i%:Qi  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), SY _='9U  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %l$W*.j|;  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", rK|*hcy  
nEndPos = " + nFileLength); '6S%9ahE  
// fileSplitterFetch[nPos.length-1].start(); J?Iq9f  
BHr|.9g]%%  
wk[ wNIu  
//等待子线程结束 NQLiWz-q  
//int count = 0; '3;v] L?G  
//是否结束while循环 n?QZFeI`  
boolean breakWhile = false; +)/ Uu3"=  
]~jN^"o_B  
`X -<$x  
while(!bStop) fN[8N$1-  
{ ?<~WO?  
write_nPos(); j_Nm87i]  
Utility.sleep(500); ]WL|~mG  
breakWhile = true; WS,7dz  
>K:u ?YD[  
X")|Uw8Kl/  
for(int i=0;i<nStartPos.length;i++) =`t^~.5  
{ M-MKk:o  
if(!fileSplitterFetch.bDownOver) ];FtS>\x  
{ |wp ,f%WK  
breakWhile = false; |NMO__l@  
break; x';u CKWV  
} (S9f/i ^  
} jw>h k  
if(breakWhile) AsxD}Nw[Z*  
break; nhH;?D3  
BIMKsF Zt  
S`= WF^  
//count++; *'8LntZf  
//if(count>4) )K0i@hM(n  
// siteStop(); X0uJNHO  
} APSgnf  
};katqzEg  
j43$]'-  
System.err.println("文件下载结束!"); S!Jh2tsg`-  
} wAF,H8 -DK  
catch(Exception e){e.printStackTrace ();} 6"QEJ  
} 9M-K]0S(  
wk $,k  
Pe ~c  
//获得文件长度 ]<trA$ 0  
public long getFileSize() !G?gsW0\h  
{ ?<%=: Yh  
int nFileLength = -1; C/tr$.2H=  
try{ EX "|H.(  
URL url = new URL(siteInfoBean.getSSiteURL()); WES#ZYtT  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wL{qD  
httpConnection.setRequestProperty("User-Agent","NetFox"); r<R4 1Fz  
bS^WhZy'(  
Zi ESlf$  
int responseCode=httpConnection.getResponseCode(); ?IhB-fd>@  
if(responseCode>=400) 9F##F-%x  
{ &|o$=Ad  
processErrorCode(responseCode); [r-}bp'Gp  
return -2; //-2 represent access is error Q!'qC*Gyfn  
} !xK=#pa  
uzU{z;  
<"tDAx  
String sHeader; I.jZ wW!r  
*yaw$oB  
raUs%Y3  
for(int i=1;;i++) 3S~(:#|  
{ SoQR#(73HK  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); gS9>N/b|  
//Utility.log(in.readLine()); R.RSQk7;  
sHeader=httpConnection.getHeaderFieldKey(i); |+f-h,  
if(sHeader!=null) P~ 0Jg# V  
{ \ v2H^j/  
if(sHeader.equals("Content-Length")) FfFak@H  
{ tw K^I6@  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $P {K2"Oc  
break; !{UTD+|=N  
} ,T5u'";  
} uofr8oL~  
else nb, 2,H  
break; =JO^XwUOo  
} MQTdk*L_]  
} 5W? PCOh\  
catch(IOException e){e.printStackTrace ();} yI;"9G  
catch(Exception e){e.printStackTrace ();} ;sOsT?)7$  
@!%n$>p/V  
_M5%V>HO  
Utility.log(nFileLength); WNX5iwm  
-K %5(Eg  
X@wm1{!  
return nFileLength; <PD?f/4 /  
} E5GJi  
}SfbCa)UO  
})F*:9i*  
//保存下载信息(文件指针位置) z~oDWANP  
private void write_nPos() /f{$I  
{ 9<1F[SS<s9  
try{ )}lRd#V  
output = new DataOutputStream(new FileOutputStream(tmpFile)); V%ii3  
output.writeInt(nStartPos.length); !PUZWO  
for(int i=0;i<nStartPos.length;i++) yW7'?  
{ J./d!an  
// output.writeLong(nPos); 2.I^Xf2  
output.writeLong(fileSplitterFetch.nStartPos); lFG9=Wf  
output.writeLong(fileSplitterFetch.nEndPos); RYR-K^;R  
} Z*! O:/B  
output.close(); ]ya; v '  
} hlbvt-C?}"  
catch(IOException e){e.printStackTrace ();} e{w>%)rcP  
catch(Exception e){e.printStackTrace ();} &l2TeC@;  
} U>qHn'M  
tD=@SX'Y  
2)0b2QbQ  
//读取保存的下载信息(文件指针位置) 7L(e h7  
private void read_nPos() @_ygnNn4R  
{ ).412I  
try{ sH#X0fG  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); hUpnI@  
int nCount = input.readInt(); @tUoD>f  
nStartPos = new long[nCount]; lx0 ~>K]  
nEndPos = new long[nCount]; Rd&9E  
for(int i=0;i<nStartPos.length;i++) ~qVz)<  
{ 7{kP}?  
nStartPos = input.readLong(); B|=|.qp$)  
nEndPos = input.readLong(); (U1]:tZ<.  
} #(;<-7M2  
input.close(); wEft4 o  
} }M>r E  
catch(IOException e){e.printStackTrace ();} fL*T3[d  
catch(Exception e){e.printStackTrace ();} j f~wBm d7  
} \FmKJ\  
(#\pQ51  
Zl/< w(f_  
private void processErrorCode(int nErrorCode) r4}*l7Q  
{ u0s8yPA  
System.err.println("Error Code : " + nErrorCode); 5N7H{vT_  
} AC%JC+  
_c(4o:  
AG6K daJ  
//停止文件下载 CON0E~"  
public void siteStop() NaUr!s  
{ []kN16F  
bStop = true; k\r(=cex6  
for(int i=0;i<nStartPos.length;i++) MmTC=/j  
fileSplitterFetch.splitterStop(); `RRE(SiKU  
E;Y;r"  
3.Gj4/f  
} m6mwyom.  
} 8P' ana  
//负责部分文件的抓取 hcCp,b  
**FileSplitterFetch.java !]` #JAL7  
*/ A Io|TD5{~  
package NetFox; wE\3$ s/{D  
_banp0ywS  
Ddju~510  
import java.io.*; cu!W4Ub<  
import java.net.*; _Xcn N:Rt  
=}!Mf'  
 |J5 =J  
public class FileSplitterFetch extends Thread { c"tJld5F_  
uGU; Y'W)  
'T=~jA7SkT  
String sURL; //File URL RJeDEYXeg  
long nStartPos; //File Snippet Start Position ef!XV7 P  
long nEndPos; //File Snippet End Position una%[jTc  
int nThreadID; //Thread's ID wN-i?Ek0;  
boolean bDownOver = false; //Downing is over R<ND=[}s  
boolean bStop = false; //Stop identical %(/!ljh_  
FileAccessI fileAccessI = null; //File Access interface 5~sx:0;  
_,74)l1  
'J)2g"T@  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException VhGs/5  
{ q=Zr>I;(Ks  
this.sURL = sURL; penlG36Q  
this.nStartPos = nStart; -Ng'<7  
this.nEndPos = nEnd; #EGA#SKoq  
nThreadID = id; owpWz6k7  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7}O.wUKw%  
} [Qt?W gPj  
2aA`f7  
f$HH:^#  
public void run() <|Yj%f  
{ uQb!=]  
while(nStartPos < nEndPos && !bStop) CI:^\-z  
{ rX7QbAB  
4M&`$Wim  
V! |qYM.  
try{ g.JN_t5  
URL url = new URL(sURL); /.Nov  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cXMhq<GkAA  
httpConnection.setRequestProperty("User-Agent","NetFox"); f;SC{2f  
String sProperty = "bytes="+nStartPos+"-"; IxR?'  
httpConnection.setRequestProperty("RANGE",sProperty); hG~reVNf  
Utility.log(sProperty); n(nBRCG)o  
2f`nMW  
5v)(8|.M  
InputStream input = httpConnection.getInputStream(); 3l<S}k@M)  
//logResponseHead(httpConnection); 'uDjFQX  
5BkV aF7Th  
. v@>JZC  
byte[] b = new byte[1024]; 5F|8?BkOL^  
int nRead; R =Ws#'  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >gKh  
{ q}BzyC=:n  
nStartPos += fileAccessI.write(b,0,nRead); g @I6$Z  
//if(nThreadID == 1) 'D1A}X  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); u,3,ck!B>@  
} Do%-B1{ri  
4n1; Bh$  
Rv,JU6>i  
Utility.log("Thread " + nThreadID + " is over!"); C${ S^v  
bDownOver = true; 8n BL\{'B[  
//nPos = fileAccessI.write (b,0,nRead); kPBV6+d~  
} p,pR!qC>  
catch(Exception e){e.printStackTrace ();} ;|p$\26S)%  
} Ch()P.n?  
} Sw`RBN[ yo  
:!;'J/B@..  
;R=.iOn  
//打印回应的头信息 @pI5lh  
public void logResponseHead(HttpURLConnection con) x6afI<dm  
{ zOEY6lAwI  
for(int i=1;;i++) &bz:K8c  
{ v1k)hFjPK  
String header=con.getHeaderFieldKey(i); @=]~\[e\  
if(header!=null) ' /Bidb?  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); aKUS5jDu  
Utility.log(header+" : "+con.getHeaderField(header)); +t4BQf  
else  HBys  
break; 9jp:k><\(c  
} ~m1P_`T  
} 5Ft5@UF~  
5G0 $  
OX%MP!#KU  
public void splitterStop() DcMJ^=r8O:  
{ 6qe*@o  
bStop = true; p_ Fy >j  
} P+t#4J  
jEc|]E  
ri C[lB  
} qjJBcu_C'S  
1iL 'V-y  
 %d Ernc$  
/* zJM S=r  
**FileAccess.java -16K7yk  
*//文件访问(定位,写) 04J}UE]Ww  
package NetFox; E$a ?LFa6  
import java.io.*; "M|P+A  
P3 c\S[F  
wpA`(+J  
public class FileAccessI implements Serializable{ d_S*#/k  
(vR 9H(#  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4RKW  
RandomAccessFile oSavedFile; ; )Kh;;e  
long nPos; C=uZ1xg*,  
krq/7|  
y5= `ap  
public FileAccessI() throws IOException jNwjK0?  
{ 6b8;}],|  
this("",0); .%'(9E  
} k^$+n_  
"I;C;}!  
wn Y$fT9  
public FileAccessI(String sName,long nPos) throws IOException c4e_6=Iv  
{ c8)/:xxl  
oSavedFile = new RandomAccessFile(sName,"rw"); $@\mpwANl  
this.nPos = nPos; h@7FY  
oSavedFile.seek(nPos); z|G9,:9  
} _u"nvgVz9  
3`O?16O  
C\_zdADUb%  
public synchronized int write(byte[] b,int nStart,int nLen) k&#a\OJ7u  
{ ]DFXPV  
int n = -1; NT%W;)6m9  
try{ ;E~4)^  
oSavedFile.write(b,nStart,nLen); ?6Cz[5\  
n = nLen; "HD+rmUEH  
} xy+QbD T  
catch(IOException e) /Y[~-Y+!,  
{ e]ig!G]  
e.printStackTrace (); STfyCtS  
} k)S.]!u&G  
3`hUo5K  
w)E@*h<Z  
return n; [MX;,%;;  
} {v aaFs  
QVZD/shq  
4A{|[}!  
} +&tgJ07A  
W-RqN!snJ8  
2^~<("+w  
/* Ot&:mT!2  
**SiteInfoBean.java (VvKGh  
*/ ZWc+),X  
package NetFox; 0uVv<Q~  
kI*(V [i  
F}Mhs17!|  
public class SiteInfoBean { @#+jMV$g  
*, Ld/O;s  
.=9 s1 ~]  
private String sSiteURL; //Site's URL I4H`YOD%  
private String sFilePath; //Saved File's Path PZ:u_*Vu`  
private String sFileName; //Saved File's Name XA0 (f*  
private int nSplitter; //Count of Splited Downloading File @ \.;b9  
L^kp8o^$  
VeiElU3  
public SiteInfoBean() ydl jw  
{//nSplitter的缺省值为5 (A k\Lm  
//default value of nSplitter is 5 Ue5O9;y]u  
this("","","",5); ir> ]r<Zl  
} '6Qy/R  
pvWau1ArNq  
)G^TW'9  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) u'Q?T7  
{ #$S}3 o  
sSiteURL= sURL; !}TMiCK  
sFilePath = sPath; WiNT;v[  
sFileName = sName; s}M= oe  
this.nSplitter = nSpiltter; A)n W  
<x%M3BTx  
xIbMs4'iEx  
} S{F-ttS"  
KHiFJ_3  
1ZJ4*bn  
public String getSSiteURL() hi{%pi&!T  
{ _cJ[ FP1  
return sSiteURL; yT /EHmJ  
} _68BP)nz>.  
,1n >U?5  
yFIy`9R  
public void setSSiteURL(String value) MKGS`X]<J  
{ UgHf*m  
sSiteURL = value; *}b]rjsj  
} e&Y0}oY  
A//?6O Jx?  
l4'~}nn(Y  
public String getSFilePath() cH`^D?#se  
{ S*W;%J5  
return sFilePath; -mNQ;zI1  
} To"dG& h  
*3{J#Q6fk3  
-<f/\U  
public void setSFilePath(String value) F%.xuLW  
{ 'E]A.3-Mt  
sFilePath = value; Dk)}|GJ()"  
} 9V!-ZG  
r((Tavn  
Y)HbxFF`/  
public String getSFileName() `"y`AY/N  
{ \^532FIw6  
return sFileName; nnCug  
} 97~K!'/^+y  
9Ld9N;rWm#  
H3FW52pjX  
public void setSFileName(String value) - V) R<  
{ )*1.eObhL  
sFileName = value; iLq#\8t^  
} /0==pLa4  
f@z*3I;  
)^;DGzG  
public int getNSplitter() >q( 5ir  
{ U{1z;lJ  
return nSplitter; Lyoor1   
} =& U`9qN  
hw,^G5m  
SE`l(-tL  
public void setNSplitter(int nCount) YB!!/ SX4  
{ 2_pz3<,\  
nSplitter = nCount; : }?{@#Z  
} _vrWj<wyf  
} 9{eBgdC  
uEd,rEB>  
'V!kL, 9ES  
/* it}-^3A M  
**Utility.java &4kM8Qh  
*/ "bX4Q4Dq  
package NetFox; 'h *Zc}Q:  
#)74X% 4(  
981!2*  
public class Utility { ])$S\fFm  
Y6eEGo"K.+  
{'~sS  
public Utility() b=LF%P  
{ g _ M-F  
njMLyT($  
p.Y$A if.  
} a$+#V=bA  
|=3 *;}  
//线程睡眠 Z=9dMND  
public static void sleep(int nSecond) 2LhE]O(_"  
{ &%e"9v2`  
try{ M {xie  
Thread.sleep(nSecond); 3 jh|y,  
} WEC-<fN|Y\  
catch(Exception e) . bG{T|  
{ 1URsHV!xcM  
e.printStackTrace (); kPJ~X0Fr{t  
} oNSz&)LP  
} hEcYpng~  
MZ^Ch   
//日志 z(UX't (q  
public static void log(String sMsg) r5)f82pQ  
{ 7ukDS]  
System.err.println(sMsg); Kq6qXc\x  
} bX{PSjD  
mh8nlB  
m){&:Hs  
public static void log(int sMsg) S A3Y:(  
{ N[{]iQ  
System.err.println(sMsg); Ja=N@&Z#  
} ^z?=?%{  
} JOHp?3"4  
<w11nB)  
+}]wLM}\UF  
/* "b;k.Fx  
**TestMethod.java ke</x+\F  
*/ XAlD ww  
package NetFox; bl9E&B/  
<on)"{W13  
;@O(z*14@  
public class TestMethod { {r X5  
~pwY6Q  
?/L1tX)  
public TestMethod() C$0 ITw  
{ ///xx/weblogic60b2_win.exe y7 <(,uT  
try{ "p2u+ 8?  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _4S7wOq5  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Z~B+*HF  
SiteFileFetch fileFetch = new SiteFileFetch(bean); E<P*QZ-C3  
fileFetch.start(); M, Po54u  
} _"`/^L`Q?  
catch(Exception e){e.printStackTrace ();} akY6D]M  
n/:Z{  
_c,&\ wl$  
} F .& *D~f  
,9+nfj  
r]Z.`}Kkm  
public static void main(String[] args) %hrsE5k^,  
{ <`b|L9  
new TestMethod(); %0go%_  
} aw;{<?*  
} ]*;RHy9  
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