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http断点续传简单实现(java)

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/* mhs%8OTN  
**SiteFileFetch.java c.>OpsF  
*/ _PP-'^ U  
package NetFox; 8p/&_<mnW  
import java.io.*; hsI9{j]f  
import java.net.*; 5fp&!HnG  
=#%Vs>G  
=jU#0FAO  
public class SiteFileFetch extends Thread { k4"O} jQO  
)G#O#Yy  
xP'"!d4^i  
SiteInfoBean siteInfoBean = null; //文件信息Bean nv: VX{%  
long[] nStartPos; //开始位置 h<!!r  
long[] nEndPos; //结束位置 ,twm)%caU  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 qx?0]!x  
long nFileLength; //文件长度 WtMDHfwqu\  
boolean bFirst = true; //是否第一次取文件 d#I; e  
boolean bStop = false; //停止标志 8Urj;KkD  
File tmpFile; //文件下载的临时信息 S;nlC  
DataOutputStream output; //输出到文件的输出流 <*ME&c gh4  
C33RXt$X  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ^X:g C9  
public SiteFileFetch(SiteInfoBean bean) throws IOException sHSg _/|  
{ 5hlS2fn  
siteInfoBean = bean; N_VWA.JHt  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); @4]dv> Z  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); - KaU@t  
if(tmpFile.exists ()) cA!o xti  
{  '^,|8A2  
bFirst = false; uC 2{ Mmy  
read_nPos(); 0qN+W&H  
} rp!{QG  
else |W|RX3D  
{ <VT|R~  
nStartPos = new long[bean.getNSplitter()]; okbW.  ~  
nEndPos = new long[bean.getNSplitter()]; [R/'hH5  
} !XF:.|  
g'.(te |  
-&np/tEu&  
;7mE%1X  
} !L@a;L  
H4ancmy  
$~1~+s0$  
public void run() e:n3@T,R  
{  U%tpNWB  
//获得文件长度 N8m3 Wy  
//分割文件 &2pa9i  
//实例FileSplitterFetch cN]g^  
//启动FileSplitterFetch线程 iE"+-z\U  
//等待子线程返回 )Tf,G[z&ge  
try{ {6;S= 9E\  
if(bFirst) oJ0ZZu?{D  
{ mX@!O[f%9e  
nFileLength = getFileSize(); bN>|4hS  
if(nFileLength == -1) ?T8^tGD[  
{ ]_:j+6i  
System.err.println("File Length is not known!"); V<t!gT#&o!  
} #pWeMt'  
else if(nFileLength == -2) jg(cpo d  
{ +J2;6t  
System.err.println("File is not access!"); T<u QhPMw  
} 7)l+h Z  
else  Y?IXV*J  
{ p}yp!(l  
for(int i=0;i<nStartPos.length;i++) b3+F~G-I"  
{ A04E <nr  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); PO]c&}/  
} o/I`L  
for(int i=0;i<nEndPos.length-1;i++) *|3G"B{w6  
{ w(!COu  
nEndPos = nStartPos[i+1]; * o#P)H  
} [^\HP] *Q{  
nEndPos[nEndPos.length-1] = nFileLength; _4X3g%nXl  
}  I8  
} !u=A9i!  
ac/<N%  
4+B OS ~  
//启动子线程 ^ZDpG2(zk  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; QlH,-]N$L  
for(int i=0;i<nStartPos.length;i++) <U2Un 0T  
{ 3t:/Guyom8  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &h;J_Ps  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), b("M8}o  
nStartPos,nEndPos,i); 7\EY&KI"0  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ifcC [.im  
fileSplitterFetch.start(); m4'x>Z  
} #PA 9bM  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7;Vqr$9)  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 80Z'1'u0  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", rLI );!^-  
nEndPos = " + nFileLength); }+GIrEDId  
// fileSplitterFetch[nPos.length-1].start(); n]v,cfn/=<  
*ZV=4[#bT  
+o}mV.&1,  
//等待子线程结束 ]Jx_bs~g  
//int count = 0; e<HHgC#J  
//是否结束while循环 o@DlK`  
boolean breakWhile = false; 5<h:kZ"S^g  
]E}eM@xdD  
}\ hz@G<  
while(!bStop) p JM&R<i:  
{ `(lD]o{,s  
write_nPos(); fz W!-  
Utility.sleep(500); 9wpV} .(  
breakWhile = true; U$wD'v3pw  
t}f,j^`e  
~cb7]^#u1l  
for(int i=0;i<nStartPos.length;i++) "\l#q$1h  
{ asKAHVT(  
if(!fileSplitterFetch.bDownOver) nlR7V.  
{ NrWgaPO)i  
breakWhile = false; =4:]V\o):'  
break; Q <2 `ek  
} Zo T8  
} s=83a{#K  
if(breakWhile) )wfqGkr=m!  
break; C0 o  
2~)r,.,  
%%hG],w  
//count++; ]seOc],4  
//if(count>4) ?j@(1",=&  
// siteStop(); R9)"%SO<y  
} \'-E[xNcWI  
V8" m_  
5PPaR|c3  
System.err.println("文件下载结束!"); e&ci\x%  
} ^#)]ICV  
catch(Exception e){e.printStackTrace ();} tQmuok4"d  
} 7s}E q~  
GfL: 0  
.[C@p`DZ  
//获得文件长度 ,]_<8@R  
public long getFileSize() p\ _&  
{ T!Z).PA#  
int nFileLength = -1; o'Kl+gw4  
try{ 0c$ ')`! m  
URL url = new URL(siteInfoBean.getSSiteURL()); 8 ;"HM5+  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YzeNr*  
httpConnection.setRequestProperty("User-Agent","NetFox"); ID8u&:  
U\x $@J  
6QG"~>v7'(  
int responseCode=httpConnection.getResponseCode(); 4-JyK%m,0  
if(responseCode>=400) W9/HM!  
{ !]t5(g_  
processErrorCode(responseCode); `xF^9;5mi  
return -2; //-2 represent access is error =.ReM_.  
} X}_Gk5q*  
Y [%<s/  
TWSx9ii!M:  
String sHeader; y4j\y ? T8  
]jgMN7  
9oTtH7%  
for(int i=1;;i++) 7)dCdO  
{ b;I zK'  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); J)._&O$  
//Utility.log(in.readLine()); 0Q!/A5z  
sHeader=httpConnection.getHeaderFieldKey(i); u Xo?  
if(sHeader!=null) x<\5Jrqt  
{ Df.eb|[{  
if(sHeader.equals("Content-Length")) OZ6:u^OS]  
{ xt1Ug~5  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .njk^,N  
break; H_>9'(  
} |}isSCt  
} %abc -q  
else v?(z4oOD/>  
break; Ff&kK5} q  
} >.&E-1[+:  
} XNQPyZ2@|b  
catch(IOException e){e.printStackTrace ();} /|>?!;   
catch(Exception e){e.printStackTrace ();} 6d/1PGB  
IH3Nkpsg  
O 4'/C]B 2  
Utility.log(nFileLength); ky@ZEp=  
=[nuesP'  
8'#L+$O &N  
return nFileLength; ErxvGB(2  
}  EHk$,bM  
_@OS,A  
y_LFkZ  
//保存下载信息(文件指针位置) AwWo,Y399h  
private void write_nPos() |./{,",  
{ ;.Y-e Q,  
try{ @wcrtf~{)&  
output = new DataOutputStream(new FileOutputStream(tmpFile)); .,<w_=  
output.writeInt(nStartPos.length); q0L\{  
for(int i=0;i<nStartPos.length;i++) *> E_lWW.  
{ {h0T_8L/  
// output.writeLong(nPos); d9q`IZqee  
output.writeLong(fileSplitterFetch.nStartPos); !nL>Ly  
output.writeLong(fileSplitterFetch.nEndPos); KpC!C9  
} Of m0{c=  
output.close(); /p$+oA+  
} TGHyBPJb  
catch(IOException e){e.printStackTrace ();} Af Y ]i  
catch(Exception e){e.printStackTrace ();} U3~rtc*  
} y 'Ah*h  
A$70!5*  
bMB*9<c~  
//读取保存的下载信息(文件指针位置) <RuLIu  
private void read_nPos() {'sp8:$a  
{ %\T#Ik~3  
try{ m\G45%m  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *R3^:Y&  
int nCount = input.readInt(); <b-OdOg  
nStartPos = new long[nCount]; |cgc^S/~H  
nEndPos = new long[nCount]; {$Z S 2 7  
for(int i=0;i<nStartPos.length;i++) Tly*i"[&  
{ SvQ!n4 $  
nStartPos = input.readLong(); *yYeqm  
nEndPos = input.readLong(); 8(g}/%1mt3  
} p# JPLCs  
input.close(); _6-N+FI  
} HT7I~]W  
catch(IOException e){e.printStackTrace ();} -f["1-A  
catch(Exception e){e.printStackTrace ();} )zkr[;j~`  
} r-o+NV  
B*:W`}G]_c  
?-JW2 E"uT  
private void processErrorCode(int nErrorCode) Q7-'5s   
{ OmlM9cXm^4  
System.err.println("Error Code : " + nErrorCode); BvP++,a&Sa  
} -?w3j9kk>  
|f1RhB  
i?861Hu  
//停止文件下载 Ffig0K+ `  
public void siteStop() (L`IL e*  
{ UJ><B"  
bStop = true; o:`^1  
for(int i=0;i<nStartPos.length;i++) `=%G&_3_<  
fileSplitterFetch.splitterStop(); PLq]\y  
o)+C4f[G4  
AnoA5H  
} |h & q  
} Ml6}47n  
//负责部分文件的抓取 'EC0|IT)c  
**FileSplitterFetch.java a fLE9  
*/ M[cAfu  
package NetFox; qtuT%?wT@Z  
}=A+W2D  
39A|6>-?  
import java.io.*; =R*IOJ  
import java.net.*; p-*{x  
=^z*p9ZB  
A3|2;4t  
public class FileSplitterFetch extends Thread { mbHMy[R  
9Zr6 KA{  
;H9 W:_ahE  
String sURL; //File URL |Xmzq X%  
long nStartPos; //File Snippet Start Position -Gjz+cRns  
long nEndPos; //File Snippet End Position 4kR;K !@k  
int nThreadID; //Thread's ID GJ:oUi  
boolean bDownOver = false; //Downing is over 2V*;=cv~z  
boolean bStop = false; //Stop identical MAQ-'s@  
FileAccessI fileAccessI = null; //File Access interface Y$_^f*sFn  
,(f({l[J}  
'p)DJUwt  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~5>TMIDiuR  
{ bnN&E?{hF1  
this.sURL = sURL; W9]0X  
this.nStartPos = nStart; *0m|`- T  
this.nEndPos = nEnd; {vk%&{D0)  
nThreadID = id; &%tW  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <) -]'@*c  
} -`$J& YU  
58R.`5B  
(:R5"|]@<x  
public void run() y5XFJj  
{ #mD_<@@  
while(nStartPos < nEndPos && !bStop) ?rziKT5OOC  
{ }{mS"  
%vbov}R  
_+Z5qUmQ  
try{ fKO@Qx]  
URL url = new URL(sURL); KN&|&51p}  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >1HXC2 Y  
httpConnection.setRequestProperty("User-Agent","NetFox"); ^S 45!mSb  
String sProperty = "bytes="+nStartPos+"-"; n8JM 0 U-  
httpConnection.setRequestProperty("RANGE",sProperty); aSI%!Vg.  
Utility.log(sProperty); i=&]%T6Qk  
)1 QOA  
9A87vs4[  
InputStream input = httpConnection.getInputStream(); / S@iF  
//logResponseHead(httpConnection); R G~GVf  
di7cCn  
kOC0d,  
byte[] b = new byte[1024]; -j1]H"-  
int nRead; *?A!`JpJn  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) nZM]EWn  
{ u95D0S  
nStartPos += fileAccessI.write(b,0,nRead); qpzyl~g:C  
//if(nThreadID == 1) dF5y' R'  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |io)?`pj  
} - Rx;"J.H  
^}`24~|y  
B~b ='jN  
Utility.log("Thread " + nThreadID + " is over!"); uMRzUK`QK  
bDownOver = true; 40z1Qkmaey  
//nPos = fileAccessI.write (b,0,nRead); yCkX+{ki  
} P6({wx  
catch(Exception e){e.printStackTrace ();} 7~;)N$d\  
} xrI9t?QaCb  
} d%K{JkD-  
ca5;Z@t$S  
`i+2YCk  
//打印回应的头信息 )`6OSB  
public void logResponseHead(HttpURLConnection con) [.6bxK  
{ B ]sVlbt  
for(int i=1;;i++) M.bkFuh  
{ vP\6=71Y  
String header=con.getHeaderFieldKey(i); / %iS\R%ca  
if(header!=null) Z~[eG"6zI  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4~8-^^  
Utility.log(header+" : "+con.getHeaderField(header)); TX7dwmt) N  
else sHPj_d#  
break; "<f?.l\+  
} L(9AcP  
} (*,R21<%  
e_g&L)  
BqDsf5}jpA  
public void splitterStop() JB=L{P J  
{ 43<i3O  
bStop = true; 8k+k\V{  
} @Kw&XKe`  
b `bg`}x  
JY,oXA6O  
} -BWWaL  
[k&7h,  
w,_LC)9  
/* O[z6W.  
**FileAccess.java }:QoYNq  
*//文件访问(定位,写) N vTp1kI]  
package NetFox; G:` So  
import java.io.*; KC%&or  
CrG!8}  
&}K%F)S  
public class FileAccessI implements Serializable{ UMT}2d%  
B\l0kiNT  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |;^$IZSsz  
RandomAccessFile oSavedFile; lR mVeq:  
long nPos; [nlq(DGJhp  
K<%8.mZ7  
p["pGsf  
public FileAccessI() throws IOException fI'+4 )@x  
{ :nfy=*M#  
this("",0); rq\<zx]au  
} UUa@7|x  
K$B~vy6E`  
66$ hdT$  
public FileAccessI(String sName,long nPos) throws IOException DZA '0-  
{ 'pO-h,{TS  
oSavedFile = new RandomAccessFile(sName,"rw"); [fELf(;(  
this.nPos = nPos; b! teSf  
oSavedFile.seek(nPos); .[1@wW&L  
} *P&lAyt6  
g>`D!n::n  
B__e*d:)!m  
public synchronized int write(byte[] b,int nStart,int nLen) .9Dncsnf,`  
{ N9M",(WTt}  
int n = -1; Vup|*d2r0E  
try{ -KfMK N~  
oSavedFile.write(b,nStart,nLen); woF {O)~X  
n = nLen; )J2UNIgN  
} ~=<uYv?0s  
catch(IOException e) " RIt  
{ !lA~;F  
e.printStackTrace (); *y$CDv  
} B]mMwqM#  
3C'6i  
$vn)(zn+  
return n; Bgp%hK  
} P{Q$(rOe  
*i!t&s  
1u(n[<WtT_  
} {Z Ld_VGW  
IGab~`c-[  
DJqJ6z:'  
/* zsR5"Vi=  
**SiteInfoBean.java =.J cIT'  
*/ dP>FXgY  
package NetFox; gv i!|!M=  
# @7 I  
)n[=)"rf  
public class SiteInfoBean { 09{s'  
a4Z e!l(  
'+'h^  
private String sSiteURL; //Site's URL @hrIu" '!  
private String sFilePath; //Saved File's Path ikb77 ?.  
private String sFileName; //Saved File's Name \((5Sd  
private int nSplitter; //Count of Splited Downloading File B@ ms Gb C  
tCA0H\';  
W1ndb:  
public SiteInfoBean() rj?c   
{//nSplitter的缺省值为5 u:B=lZ[  
//default value of nSplitter is 5 /;!I.|j  
this("","","",5); Xn>>hzj-x?  
} pRUQMPn (  
6z:/ma^  
SwaPRAF  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0F%?< : &  
{ yL -}E  
sSiteURL= sURL; O`aNNy  
sFilePath = sPath; \MPbG$ ^  
sFileName = sName; 2]FRIy d  
this.nSplitter = nSpiltter; tCPK_Wws?Z  
"5?1S-Vl  
PzhC *" i}  
} 3Wx\Liw,  
C@<gCMj,"  
#7}YSfm^6  
public String getSSiteURL() xr7M#n  
{ a`?Vc}&  
return sSiteURL; 2vb qz  
} MD3iWgM  
^&$86-PB/  
Tks"GlE*D  
public void setSSiteURL(String value) '$J M2 u  
{ {) sE;p-  
sSiteURL = value; }U4mXkZF  
} iM9^.  
xO,;4uE  
W5~!)Ec  
public String getSFilePath() :_=YH+bZ  
{ 6s ~!B{Q  
return sFilePath; WT3g31  
} X\i;j!;d  
S/RChg_L5  
(Jk[%_b>_  
public void setSFilePath(String value) JZE@W -2  
{ j%J>LeTca  
sFilePath = value; ;18u02z^  
} /Ei e5p  
|2rOV&@l9  
'C#[iRG4  
public String getSFileName() k2PK4Ua_}q  
{ Z)@[N 6\?  
return sFileName; >ffC?5+  
} 9]1LwX!M2  
* X}2  
s#")hMJQ  
public void setSFileName(String value) .b^!f<j  
{ >.G#\w  
sFileName = value; 7u5H o`  
} 3f~znO  
2iOYC0`!  
]D=fvvST  
public int getNSplitter() W/~q%\M {  
{ )UVekkq>Q  
return nSplitter; i->G {_gH  
} !@ y/{~Gu  
[X8EfU}  
#v9+9X`1L  
public void setNSplitter(int nCount) =qL^#h83y  
{ 2~B5?(g  
nSplitter = nCount; ugTnz$  
} \=xS?(v!  
} RZ ?SiwE  
|zd5P  
w|*D{`O  
/* rls{~ZRl  
**Utility.java u]ps-R_$G  
*/ +4rd N\.  
package NetFox; m| 7v76(  
oJ/=&c  
sBqOcy  
public class Utility { VwK7\j V  
Ai5+ ;8z+  
K\s<<dRa  
public Utility() wwJs_f\  
{ j#Lj<jX!xR  
FP*kA_z$  
FT-=^VA\  
} LB}J7yEQvj  
xe3Jxo !U  
//线程睡眠 !T8sWMY  
public static void sleep(int nSecond) 1rLxF{,  
{ lLglF4  
try{ a$bE2'cb  
Thread.sleep(nSecond); |+>U91!  
} I9`ZK2S  
catch(Exception e) 9jNh%raG|  
{ tAujm*|&  
e.printStackTrace (); ^),t=!;p  
} YRd`G3J  
} >RpMw!NT  
k72NXagh  
//日志 YNKvR  
public static void log(String sMsg) W ,v0~  
{ wqJl[~O$  
System.err.println(sMsg); pEX Q  
} 1&9w]\Ae7l  
e#F3KLSL`  
W{j(=<|<  
public static void log(int sMsg) N%e^2O)  
{ ]&P 4QT)f  
System.err.println(sMsg); HNlW.y"  
} $'<$:;4b3  
} VRSBf;?  
*m`x/_y+  
M 8(w+h{  
/* Dqd2e&a\  
**TestMethod.java \0&$ n  
*/ %5@> nC?`[  
package NetFox; :1@jl2,  
kr!>rqN5  
N3oa!PE  
public class TestMethod { !:tr\L {  
I#7H)^us  
D-x*RRkpp  
public TestMethod() Ra:UnA  
{ ///xx/weblogic60b2_win.exe vmo!  
try{ [ <k&]Kv  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `G:hC5B  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); j8rxhToC  
SiteFileFetch fileFetch = new SiteFileFetch(bean); h%v qt~0  
fileFetch.start(); mC?}:W M@  
} 1|:;~9n<t  
catch(Exception e){e.printStackTrace ();} uX&h~qE/  
lZ <D,&  
?Jgqb3+!o  
} C 20VSwd  
}h8U.k?v  
F5M|QX@-  
public static void main(String[] args) 9F~5Ht  
{ X\*H7;k,  
new TestMethod(); "1%k"+&  
} <DII%7q,6/  
} PGVP0H+RV  
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