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http断点续传简单实现(java)

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/* g,!6, v@  
**SiteFileFetch.java DUxj^,mf,  
*/ ]N^a/&} *  
package NetFox; G:QaWqUb  
import java.io.*; @""aNKA^r>  
import java.net.*; ;k<g# She  
"3A.x1uQ  
DDT)l+:XP  
public class SiteFileFetch extends Thread { D0D0=s  
%11&8Fp1s  
V&E)4KBOs  
SiteInfoBean siteInfoBean = null; //文件信息Bean X9#;quco@  
long[] nStartPos; //开始位置 AAE8j.  
long[] nEndPos; //结束位置 Tt.wY=,K  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Q&;dXE h  
long nFileLength; //文件长度 1;R1Fj&  
boolean bFirst = true; //是否第一次取文件 $UAmUQg)}_  
boolean bStop = false; //停止标志 CxC&+';  
File tmpFile; //文件下载的临时信息 LoQm&3/  
DataOutputStream output; //输出到文件的输出流 #N?EPV$  
xZ} 1dq8  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) vl8Ums} +  
public SiteFileFetch(SiteInfoBean bean) throws IOException SNB >  
{ J)iy6{0"  
siteInfoBean = bean; WhsTKy&E  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Rw\ LVRdA  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); p `)(  
if(tmpFile.exists ()) E-_FxBw  
{ mYf7?I~  
bFirst = false; wIIxs_2Q0c  
read_nPos(); C d)j %  
} E=.4(J7K  
else w%&lCu@v  
{ _Kg:jal  
nStartPos = new long[bean.getNSplitter()]; j()<.h;'  
nEndPos = new long[bean.getNSplitter()]; +(*S@V$c  
} ;#G)([  
A>8uLO G}  
.olDmFQD  
=#||&1U$  
} Q<.84 7 )  
<o8j+G)K#  
^b=9{.5  
public void run() ^~k2(DLk  
{ @bQf =N+  
//获得文件长度 sHx>UvN6  
//分割文件 pJ7M.C!  
//实例FileSplitterFetch ."<mL}Fi(  
//启动FileSplitterFetch线程 vkWh2z  
//等待子线程返回 ]42bd  
try{ u/3 4E=  
if(bFirst) C~Fdo0D  
{ p}%T`e=Z9  
nFileLength = getFileSize(); 01VEz 8[\  
if(nFileLength == -1) M[N$N`9  
{ :<l(l\MC  
System.err.println("File Length is not known!"); ]p/f@j?LU  
} (5y+g?9d;  
else if(nFileLength == -2) -NW7ncB|  
{ Sdl1k+u  
System.err.println("File is not access!"); u6{= Z:  
} ,*SoV~  
else [hE0 9W  
{ j] \3>.  
for(int i=0;i<nStartPos.length;i++) Z?yMy zT  
{ hm"i\JZ3N  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Z<6XB{Nh\  
} 3[plwe  
for(int i=0;i<nEndPos.length-1;i++) 1'wwwxe7  
{ u-g2*(ZT  
nEndPos = nStartPos[i+1]; O`_!G`E  
} zWYm* c"n\  
nEndPos[nEndPos.length-1] = nFileLength; e"9 u}-Q@  
} jEwfa_Q%  
} zi7,?bD  
al<[iZ  
6KuB<od  
//启动子线程 4<b=;8  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,;LxFS5\  
for(int i=0;i<nStartPos.length;i++) t .*z)N  
{  B@Acm  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z DDvXz  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 42X N*br  
nStartPos,nEndPos,i); ;Z%PBMa  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \~|+*^e)  
fileSplitterFetch.start(); R0dIxG%  
} q 65mR!)  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), UV}\#86!  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); UX3 ]cr  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", {[~cQgCI  
nEndPos = " + nFileLength); 0F$;]zg  
// fileSplitterFetch[nPos.length-1].start(); dc[w`  
(\^| @  
H4[];&]xr  
//等待子线程结束 DK8eFyG^2  
//int count = 0; <BoDLvW>  
//是否结束while循环 Y)*5M  
boolean breakWhile = false; W`HO Q  
oG5 :]/F  
Ig9yd S-.  
while(!bStop) ]B'Ac%Rx  
{ 88\0opL-  
write_nPos(); jb~2f2vUa  
Utility.sleep(500); sHC4iMIw  
breakWhile = true; X2>qx^jT  
?;1^8 c0  
t?J Y@hT*  
for(int i=0;i<nStartPos.length;i++) bvZTB<rA  
{ KLqn`m`O;  
if(!fileSplitterFetch.bDownOver) 6q^Tq {I  
{ ].Mr&@  
breakWhile = false; @]$qJFXx  
break; "vVL52HwB  
} :2#8\7IU^'  
} MRzrZZ%LQ  
if(breakWhile) .I%p0ds1r  
break; sU>!sxW  
)Ih '0>=  
LwDm(gG  
//count++; &w@~@]  
//if(count>4) fAMJFHW  
// siteStop(); axT-  
} r,^}/<*  
H]v"_!(\  
(ATvH_Z  
System.err.println("文件下载结束!"); Y@WCp  
} ? U~}uG^  
catch(Exception e){e.printStackTrace ();} q}Wd`>VDR  
} QIl![%  
'^Kmfc  
" jefB6k9h  
//获得文件长度 -cW`qWbd  
public long getFileSize() xsjJ8>G  
{ .O9 A[s<  
int nFileLength = -1; 2K/+6t}  
try{ pyPS5vWG  
URL url = new URL(siteInfoBean.getSSiteURL()); Of| e]GR  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); = ~{n-rMF  
httpConnection.setRequestProperty("User-Agent","NetFox"); Sb_T _m  
nv WTx4oy  
yP:/F|E$  
int responseCode=httpConnection.getResponseCode(); 9d ZE#l!Q  
if(responseCode>=400) slSQ\;CDA  
{ Qg]8~^ Q<  
processErrorCode(responseCode); nsChNwPX  
return -2; //-2 represent access is error W)rE_tw,|  
} z0ULB? *"  
u+7B-l=u*  
YLc 2:9  
String sHeader; `V N $ S  
EA )28]Y.  
_H#l&bL@C  
for(int i=1;;i++) )u{)"m`&[J  
{ <.c@l,[.z  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); JDO5eEwj  
//Utility.log(in.readLine()); v]*(Wd~|  
sHeader=httpConnection.getHeaderFieldKey(i); FS.z lk\D=  
if(sHeader!=null) "zJGYBen  
{ =}@m$g  
if(sHeader.equals("Content-Length")) F12tOSfu*  
{ xW84g08_,  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); TF %8pIg>Z  
break; :Uu Py|>  
} B Z:H$v  
} @&f3zq  
else "z+Z8l1.  
break; S30@|@fTz  
} H*U\P2C!)  
} !X 3/2KRP7  
catch(IOException e){e.printStackTrace ();} p^_E7k<ag  
catch(Exception e){e.printStackTrace ();} [oOA@  
#A|~s;s>N  
.hh 2II  
Utility.log(nFileLength); Up|\&2_  
ZB-+ bY  
.F'fBT` $  
return nFileLength; (n{sp  
} -e_+x'uF  
5[WhjTo  
{Kp<T  
//保存下载信息(文件指针位置) PPCZT3c=  
private void write_nPos() Uk5O9D0 He  
{ 5- Q`v/w;  
try{ H!dUQ  
output = new DataOutputStream(new FileOutputStream(tmpFile)); MxiU-  
output.writeInt(nStartPos.length); ailje  
for(int i=0;i<nStartPos.length;i++) dvUBuY^[  
{ K`PmWxNPh  
// output.writeLong(nPos); V'h O  
output.writeLong(fileSplitterFetch.nStartPos); 7#Qa/[? D  
output.writeLong(fileSplitterFetch.nEndPos); -C$Z%I7 0  
} /*GRE#7S  
output.close(); cK.T=7T  
} md[FtcY\  
catch(IOException e){e.printStackTrace ();} EXz5Rue LV  
catch(Exception e){e.printStackTrace ();} tK&.0)*=  
} )2X ng_,  
X-di^%<  
ZyqTtA!A  
//读取保存的下载信息(文件指针位置) JL1%XQ i  
private void read_nPos()  z"BV+  
{ rVkoj;[  
try{ |Iy55~hK`  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); OwGl&  
int nCount = input.readInt(); t/cj z/]  
nStartPos = new long[nCount]; 1r}fnT<  
nEndPos = new long[nCount]; =+gp~RR,  
for(int i=0;i<nStartPos.length;i++) NF=FbvNe  
{ /p') u3  
nStartPos = input.readLong(); @]f"X>  
nEndPos = input.readLong(); . FT*K[+ih  
} n<:/ X tE  
input.close(); #)%N+Odnr  
} zOq~?>Ms6  
catch(IOException e){e.printStackTrace ();} )@Yp;=l  
catch(Exception e){e.printStackTrace ();} f}bUuQrH-!  
} ]>@; 2%YvY  
 l;>#O  
V"VWHAu*.w  
private void processErrorCode(int nErrorCode) 3OHP-oa.  
{ 9frx60  
System.err.println("Error Code : " + nErrorCode); r @~T}<I  
} -"5x? \.{m  
o}5:vi]  
Yfy6o6*:  
//停止文件下载 8xmw-s)  
public void siteStop() #&">x7?5  
{ $P]% Px!x  
bStop = true; HSx~Fs^J  
for(int i=0;i<nStartPos.length;i++) c1/G yq  
fileSplitterFetch.splitterStop(); Sm#;fx+  
vII&v+C  
U-TwrX  
} H<`[,t  
} *Rshzv[  
//负责部分文件的抓取 *MkhRLw\,  
**FileSplitterFetch.java 6__@?XzJ  
*/  L}AR{  
package NetFox; q 9qmz[  
<C6/R]x#  
lg;Y}?P  
import java.io.*; `<t{NJ&f  
import java.net.*; 'O`jV0aa'  
;:*o P(9k  
{549&]/o  
public class FileSplitterFetch extends Thread { "}K/ b  
BmrP]3W?  
}Iub{30mp  
String sURL; //File URL 5S7`gN.  
long nStartPos; //File Snippet Start Position 1 7{]QuqNF  
long nEndPos; //File Snippet End Position ^g[\.Q  
int nThreadID; //Thread's ID nx=#QLi  
boolean bDownOver = false; //Downing is over "<6pp4*I  
boolean bStop = false; //Stop identical [RD ^@~x  
FileAccessI fileAccessI = null; //File Access interface !gy'_Y  
Hi|2z5=V  
<Xy8}Z`s  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException oAWk<B(@  
{ QAi(uL5   
this.sURL = sURL; Yx&cnDx  
this.nStartPos = nStart; J+\F)k>r  
this.nEndPos = nEnd; ,@='.Qs4g  
nThreadID = id; ao{>.b  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 P; }Z 3!  
} B\|>i~u(  
v}z o v Ei  
LO.4sO  
public void run() zx-+u7qKH  
{ :G^`LyOM  
while(nStartPos < nEndPos && !bStop) ENC_#- 1x  
{ =(v!pEF  
F.A<e #e?  
^&&dO*0{  
try{ g) v"nNS  
URL url = new URL(sURL); n{BC m %  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ejo4mQ]a  
httpConnection.setRequestProperty("User-Agent","NetFox"); j)-D.bY0  
String sProperty = "bytes="+nStartPos+"-"; ZX-9BJ`Q  
httpConnection.setRequestProperty("RANGE",sProperty); jT: :o  
Utility.log(sProperty); JIb<>X,  
Pms3X  
xOT'4v&.  
InputStream input = httpConnection.getInputStream(); xxkP4,(p  
//logResponseHead(httpConnection); 9,`mH0jP  
,zXL8T  
#EHBS~^  
byte[] b = new byte[1024]; qoZ*sV  
int nRead; 6j"(/X|Ex5  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +8^9:w0}  
{ [=U7V;5($  
nStartPos += fileAccessI.write(b,0,nRead); 20?i4h_  
//if(nThreadID == 1) =_":Z!_  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V2VsJ  
} h!K B%4V  
IJ4"X#Q/  
%- A8`lf<  
Utility.log("Thread " + nThreadID + " is over!"); 2)j\Lg_M  
bDownOver = true; b V9Z[[\  
//nPos = fileAccessI.write (b,0,nRead); Y sr{1!K  
} ys#M* {?  
catch(Exception e){e.printStackTrace ();} eaX`S.!jR  
} ePs<jrB<  
} <;=Y4$y[  
J+IW  
tMAa$XrZj  
//打印回应的头信息 /kw4":{]  
public void logResponseHead(HttpURLConnection con) >t D-kzN  
{ ik$wS#1+L  
for(int i=1;;i++) J~_p2TZJ\3  
{ 2M&4]d  
String header=con.getHeaderFieldKey(i); i[\[xfk  
if(header!=null) >^-[Mpa(*  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,x Tbt4J  
Utility.log(header+" : "+con.getHeaderField(header)); k2t?e:)3zr  
else w:Lu  
break; _23sIUN c3  
} ;*Rajq  
} NWAF4i&$  
Xx'>5d>  
y5Pw*?kn  
public void splitterStop() gE ,j\M*  
{ WN?T*bz2  
bStop = true; fwq|8^S@  
} ^mJvB[ u|  
e< CPaun  
"^XN"SUw  
} Q}=RG//0*  
3Aj_,&X.@(  
c%Gz{':+  
/* zr[~wM  
**FileAccess.java 19N:9;Ixz  
*//文件访问(定位,写) Bw_Ih|y,w  
package NetFox; &)X<yd0  
import java.io.*; <rC#1wR4  
KPR{5  
3?O| X+$p  
public class FileAccessI implements Serializable{ @wFm])}0  
Cfi2N V  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 z9'0&G L  
RandomAccessFile oSavedFile; 9~; Ju^b  
long nPos; xlwsZm{V  
'I<j`)4`d  
L3GJq{t  
public FileAccessI() throws IOException 'D/AL\1{p(  
{ +.N;h-'  
this("",0); bv+e'$U3  
} * QR7t:([  
Hug{9Hr3.  
7S1!|*/ I  
public FileAccessI(String sName,long nPos) throws IOException Dw #&x/G  
{ e{} o:r  
oSavedFile = new RandomAccessFile(sName,"rw"); 8 6+>|  
this.nPos = nPos; DA wzXsx  
oSavedFile.seek(nPos); (mD]}{>  
} SW; b E  
]rNfr-  
+[qkG. O  
public synchronized int write(byte[] b,int nStart,int nLen) L_.}z)S[\  
{ u!-eP7;7  
int n = -1; 0*AlLwO  
try{ <+b:  
oSavedFile.write(b,nStart,nLen); +>3c+h,%.  
n = nLen; rx;U/)~#<  
} W" !amMQ  
catch(IOException e) 62 _$O"  
{ i4pJIb  
e.printStackTrace (); 0K2[E^.WN  
} :RQ[(zD]  
# R&[+1=9j  
sy`s$E d!  
return n; 6wd]X-G++  
} &7W6IM   
g.]'0)DMW  
i\ Vpp8<B  
} d J!o/y6  
</=PN1=A  
e||_j  
/* vj b?N  
**SiteInfoBean.java l xfdJNb  
*/ L C7LO  
package NetFox; d0=nAZZ  
^pjez+  
y|dXxd9  
public class SiteInfoBean { z3C^L  
:=Q|gRTL*  
>gZz`CH  
private String sSiteURL; //Site's URL +B m+Pj>  
private String sFilePath; //Saved File's Path yq}{6IyZ^  
private String sFileName; //Saved File's Name k:TfE6JZ  
private int nSplitter; //Count of Splited Downloading File w!}1oy  
9CNHjs+-}s  
.+Ej%|l%  
public SiteInfoBean() Tpukz_F  
{//nSplitter的缺省值为5 8joQPHkI\  
//default value of nSplitter is 5 ^ ?=K)  
this("","","",5); pt R  
} 752wK|o0|;  
h9I )<_}R  
C6VoOT )\  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \uk#pL  
{ FZ9<Q  
sSiteURL= sURL; %wf|nnieZ  
sFilePath = sPath; #CPPdU$  
sFileName = sName; `X='g96C1  
this.nSplitter = nSpiltter; {h"\JI!  
 YBD{l  
`I8^QcP  
} .A\\v6@  
o"FiM5L^.  
mr!I}I7x&x  
public String getSSiteURL() sAoM=n}!  
{ mM} Ukmy  
return sSiteURL; n@;x!c< +  
} FIjET1{  
rcZ SC3  
2?T:RB}  
public void setSSiteURL(String value) XKX,7  
{ Pm^N0L9?q  
sSiteURL = value; tb0E?&M  
} DOVX$N$3  
F2$bUY  
r^t{Ii ~  
public String getSFilePath() CS\tCw\Y  
{ kI 3zYD^:  
return sFilePath; B)]{]z0+`  
} DBBBpb~~  
Mlw9#H6  
\Byk`} 9  
public void setSFilePath(String value) 7f%Qc %B  
{ 0l: pWc  
sFilePath = value; Ue#yDTjc  
} uq4s bkP  
2A}uqaF  
bH/pa#G(  
public String getSFileName() 2 dD<]  
{ loUwR z  
return sFileName; _S2^;n?  
} (kQ.tsl  
OawrS{  
BZ+ mO  
public void setSFileName(String value) yVI;s|jG  
{ cNo4UZvr  
sFileName = value; 2c~?UK[1  
} z|]oM#Gt  
S"^KJUUc  
//M4Sq(  
public int getNSplitter() %HF$  
{ ' ?G[T28  
return nSplitter; ^ wF@6e7/&  
} Z!-<rajl  
bEQtVe@`  
to!W={S<ol  
public void setNSplitter(int nCount) q 9brpbg_  
{ dA)4(0o8fD  
nSplitter = nCount; <`xRqe:&9  
} ]X: rby$  
} @yn^6cE  
{?f^  
JXY!c\,  
/* *[xNp[4EU  
**Utility.java (Cl`+ V  
*/ Iq0 #A5U%  
package NetFox; L.0} UXd  
r$r&4d Y  
L_gsG|xX  
public class Utility { Kcw1uLb  
2rj/wakd  
n$jf($*  
public Utility() jAOD&@z1  
{ 5h>t4 [~  
l( ?Yx  
* TR ~>|  
} 6WEu(}=  
1a;&&!X  
//线程睡眠 BXX1G  
public static void sleep(int nSecond) 9p9-tJfH.  
{ R,ddH[3  
try{ }$1Aw%p^  
Thread.sleep(nSecond); Gq^#.o]  
} {y7,n  
catch(Exception e) ii]'XBSVd  
{ fSzX /r  
e.printStackTrace (); 21G:!t4/?n  
} C 6wlRvWn  
} n`g:dz  
RYKV?f#[H  
//日志 +hd1|qa4  
public static void log(String sMsg) 2`w\<h  
{ s`"ALn8m  
System.err.println(sMsg); .X(ocs$}  
} G/C5o=cY  
0!,)7  
N0G-/  
public static void log(int sMsg) z/t:gc.  
{  \ l8$1p  
System.err.println(sMsg); d<l-Ldle  
} {cBLm/C  
} G.c@4Wz+  
?4}EhXR(  
_G5M Q%z  
/* yy-\$<j  
**TestMethod.java +qEvz<kch  
*/ !T 3 Esv  
package NetFox; Ig6>+Mw  
mLn =SU{#  
rKys:is  
public class TestMethod { :cK;|{f  
R0*+GIRA(  
a4M`Bk;mb  
public TestMethod() R!.HS0i.  
{ ///xx/weblogic60b2_win.exe c~UYs\  
try{ ^6 sT$set  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |_;Vb  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); D;Jb' Be  
SiteFileFetch fileFetch = new SiteFileFetch(bean); v`$9;9  
fileFetch.start(); #Rdq^TGMi;  
} nNff~u)I  
catch(Exception e){e.printStackTrace ();} K*Tvo `  
GcPhT  
md/Z[du:'  
} k&P_ c  
GX lFS#`  
'yM)>]u"  
public static void main(String[] args) $zBG19 [%  
{ \HOOWaapN  
new TestMethod(); Lay+)S.ta[  
} B1A5b=6G<  
} HSOdqjR*  
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