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http断点续传简单实现(java)

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/* &[23DrI8  
**SiteFileFetch.java aHwrFkn  
*/ vV8 y_  
package NetFox; kmo3<'j{  
import java.io.*; -L1{0{Z  
import java.net.*; ;Q? Qwda  
UAUo)VVi"  
)v0m7L v#/  
public class SiteFileFetch extends Thread { A%%WPBk{O  
E xY ~.  
zF\k*B  
SiteInfoBean siteInfoBean = null; //文件信息Bean a8A8?:  
long[] nStartPos; //开始位置 !oM 1  
long[] nEndPos; //结束位置 }3M\&}=8  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 &d9";V"E  
long nFileLength; //文件长度 *hFT,1WE=+  
boolean bFirst = true; //是否第一次取文件 vF1] L]z:?  
boolean bStop = false; //停止标志 LD]XN'?"W  
File tmpFile; //文件下载的临时信息 gd/W8*NFR  
DataOutputStream output; //输出到文件的输出流 l,,5OZw  
9K FWa0G  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) L!-T`R8'c  
public SiteFileFetch(SiteInfoBean bean) throws IOException \CU.'|X  
{ >E[cl\5$E  
siteInfoBean = bean; 6M259*ME  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); %hcY [F<  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 6 )xm?RK  
if(tmpFile.exists ()) eUx|_*`  
{ Y~fds#y0  
bFirst = false; S(9fGh  
read_nPos(); =;^2#UxXA&  
} ]7c715@  
else IuB0C!'  
{ } Tp!Ub\Cc  
nStartPos = new long[bean.getNSplitter()]; (Cqhk:F  
nEndPos = new long[bean.getNSplitter()]; 1_XdL?h#o  
} $I>.w4G}  
Sf lHSMFw  
b_cD >A  
<:>a51HBX  
} Jr 9\j3J{  
6S<J'9sE  
+<8r?d2  
public void run() e9N"{kDs6  
{ &YqgMC  
//获得文件长度 dM#\h*:=  
//分割文件 o!\Vk~Vi&  
//实例FileSplitterFetch A GS?<6W-  
//启动FileSplitterFetch线程 n#bC ,  
//等待子线程返回 TJ2$ Z  
try{ N[ E t  
if(bFirst) 80 i<Ij8J  
{ ndW? ?wiM  
nFileLength = getFileSize(); z9'ME   
if(nFileLength == -1) ]NG`MZ  
{ <E!M<!h  
System.err.println("File Length is not known!"); ? vk;b!  
} 3QU<vdtr  
else if(nFileLength == -2) o;_v'  
{ l9#M`x9  
System.err.println("File is not access!"); fZT=q^26  
} ^Shz[=fd  
else @ 5|F:J  
{ ` *h-j/M  
for(int i=0;i<nStartPos.length;i++) rjx6Ad/\  
{ 1i#M(u_  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); f!0*^d  
} 6'+3""\  
for(int i=0;i<nEndPos.length-1;i++) Y2QlK1.8V  
{ l#V"14y  
nEndPos = nStartPos[i+1]; O .m; a_  
} |f?tyQ  
nEndPos[nEndPos.length-1] = nFileLength; 9m%[ y1v0  
} b2r@vZ]D  
} [bH6>{3u  
 K7 U`  
Fl<BCJY  
//启动子线程  ()=  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; iK= {pd  
for(int i=0;i<nStartPos.length;i++) I[@}+p0  
{ N[ z7<$$  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), / ~w\Npf0  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5e6]v2 k  
nStartPos,nEndPos,i); G8Ns?  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y]+i. 8[  
fileSplitterFetch.start(); \C~Y  
} 50uNgLs  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /i"L@t)\t  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); YeptYW@xfw  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _;L9&>!p6  
nEndPos = " + nFileLength); ^MKvZ DOP  
// fileSplitterFetch[nPos.length-1].start(); 9ZeTS~i  
D CcM~  
'8}*erAg  
//等待子线程结束 ja#E}`wC4  
//int count = 0; ]fnc.^{  
//是否结束while循环 o!gl :izb  
boolean breakWhile = false; =K- B I  
m9a(f>C  
<Gr{h>b  
while(!bStop) Qt+ K,LY  
{ -|"mB"Dc  
write_nPos(); w8%<O^wN,  
Utility.sleep(500); 1|q$Wn:*  
breakWhile = true; )$]_;JFr  
uIiE,.Uu}  
gH(,>}{^K  
for(int i=0;i<nStartPos.length;i++) K8ecSs}}J  
{ b'3w.%^  
if(!fileSplitterFetch.bDownOver)  (/-2bO  
{ /{."*jK  
breakWhile = false; 9~SfZ,(  
break; A<ur20   
} wFnIM2a,  
} B|/=E470G  
if(breakWhile) cX 9 !a,  
break; 4 B"tz!  
p. SEW5  
&S>m +m'  
//count++; V<ziJ7H/  
//if(count>4) am]$`7R5d  
// siteStop(); W}50E.\#  
} Ze~^+ EE  
Rjqeuyj:  
_%?}e|epy  
System.err.println("文件下载结束!"); '+hiCX-_  
} qfd/t<?|D  
catch(Exception e){e.printStackTrace ();} Cb%?s  
} Q"h/o"-h  
2,{m>fF  
ypSW9n  
//获得文件长度 Mm;kB/ 1  
public long getFileSize() Jlj=FA`  
{ %oJ_,m_(  
int nFileLength = -1; CE=&ZHt9  
try{ l&R~ I6^E  
URL url = new URL(siteInfoBean.getSSiteURL()); EC<g7_0F  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3P2H!r  
httpConnection.setRequestProperty("User-Agent","NetFox"); Gc^w,n[E  
Fo|6 PoSo  
jeFX?]Q  
int responseCode=httpConnection.getResponseCode(); ^i&sQQ( {  
if(responseCode>=400) a^ hDxeG  
{ xX.fN7[  
processErrorCode(responseCode); k1e0kxn  
return -2; //-2 represent access is error "94e-Nx  
} kAsYh4[  
f"\G"2C  
q"7rd?r52  
String sHeader; D(yU:^L  
U p=J&^.  
O8%+5l`T!  
for(int i=1;;i++) =;#+8w=^  
{ u 0(H!  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); I kv@}^p 7  
//Utility.log(in.readLine()); $p#)xx7  
sHeader=httpConnection.getHeaderFieldKey(i); \dO9nwa?  
if(sHeader!=null) W3Oj6R  
{ u,mC`gz  
if(sHeader.equals("Content-Length")) 4D=p#KZ  
{ gXBC= ?jl  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Q x}\[  
break; [xe(FFl+  
} g <S&sYF5  
} L  #c*)  
else Q(=} PF  
break; h; ?=:(  
} `dO)}}| y  
} Xxhzzm-B  
catch(IOException e){e.printStackTrace ();} 00X~/'!  
catch(Exception e){e.printStackTrace ();} \bNN]=  
e"Kg/*Ji1  
Y3KKskhLx  
Utility.log(nFileLength); .aTu]i3l_  
E&ou(Q={  
XUTI0  
return nFileLength; DC4O@"  
} _+7 3Y'  
b9b384Q1O  
gmtp/?>e  
//保存下载信息(文件指针位置) Jn!-Wa,  
private void write_nPos() hfw$820y[  
{ \Jq$!foYx  
try{ ^x8*]Sz#x  
output = new DataOutputStream(new FileOutputStream(tmpFile)); }q7rR:g  
output.writeInt(nStartPos.length); ;;#28nV  
for(int i=0;i<nStartPos.length;i++) //T1e7)  
{ `}<x"f7.z  
// output.writeLong(nPos); GvQKFgO6h  
output.writeLong(fileSplitterFetch.nStartPos); /Z`("X?_Kf  
output.writeLong(fileSplitterFetch.nEndPos); E_k<EQ%r  
} LE#ko2#ke  
output.close(); mhU ?N  
} U\dq Mp#Wy  
catch(IOException e){e.printStackTrace ();} {8`V5:  
catch(Exception e){e.printStackTrace ();} 6vy(@z  
} =pSuyM'  
Zt;3HY=y  
I.#V/{J  
//读取保存的下载信息(文件指针位置) AT*J '37  
private void read_nPos() 7 L2$(d4  
{ |&!04~s;E  
try{ 0*G =~:  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *q**,_?;  
int nCount = input.readInt();  |e49F  
nStartPos = new long[nCount]; u By[x 0  
nEndPos = new long[nCount]; =qG%h5]n  
for(int i=0;i<nStartPos.length;i++) cXP*?N4C f  
{ t6m&+N  
nStartPos = input.readLong(); `P/7Mf  
nEndPos = input.readLong(); |Rk9W  
} Z{&dzc  
input.close(); v w(X9xa  
} tgeX~.  
catch(IOException e){e.printStackTrace ();} #( G>J4E,  
catch(Exception e){e.printStackTrace ();} aLa{zB  
} +$_.${uwV  
}e[;~g\&  
n~`1KC4  
private void processErrorCode(int nErrorCode) zb<YYJ]  
{ OAx5 LTd  
System.err.println("Error Code : " + nErrorCode); ;QZ}$8D6Q  
} E&js`24 &  
@q8h'@sX  
4R<bfZ43  
//停止文件下载 y8~/EyY|^  
public void siteStop() (|Zah1k&]  
{ e0rh~@E  
bStop = true; Qy< ~{6V  
for(int i=0;i<nStartPos.length;i++) ICq  
fileSplitterFetch.splitterStop(); 9*`(*>S  
/XEt2,sI9  
qRk<1.  
} Zw4z`x1f  
} /O@TqH  
//负责部分文件的抓取 R1A|g =kF  
**FileSplitterFetch.java z''ITX)oG  
*/ $"#2hVO  
package NetFox; 8nKZ   
z _A]mJ  
04npY+1 8%  
import java.io.*; -l)u`f^n|  
import java.net.*; Q:rQ;/b0/  
Xx)PyO  
b# v+_7  
public class FileSplitterFetch extends Thread { .lbo\v}2W  
LHJ}I5zv  
) H HBf<  
String sURL; //File URL 8Qm%T7]UFb  
long nStartPos; //File Snippet Start Position k+nfW]UNF  
long nEndPos; //File Snippet End Position ~6bf-Wg'X  
int nThreadID; //Thread's ID ! J7ExfEA  
boolean bDownOver = false; //Downing is over 5}v<?<l9\  
boolean bStop = false; //Stop identical RH^!7W*  
FileAccessI fileAccessI = null; //File Access interface u( kacQ7  
',>Pz+XKc  
jPum2U_  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException J]m[0g7O_  
{ @cc4]>4  
this.sURL = sURL; G&7!3u  
this.nStartPos = nStart; Dej_(Dz_S  
this.nEndPos = nEnd; 0<^!<i(%  
nThreadID = id; d<,'9/a>  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 = ^NTHc^*  
} 16pk4f8  
L'A>IBrz  
1\XR6q:2  
public void run() >5%;NI5 G  
{ >)+ -:  
while(nStartPos < nEndPos && !bStop) 3_5]0:?]-  
{ ZjB]pG+  
2*[Gm e  
$27QY  
try{ N?Nu'  
URL url = new URL(sURL); }I )%Gw  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |O!G[|/3  
httpConnection.setRequestProperty("User-Agent","NetFox"); kuX{2h*`  
String sProperty = "bytes="+nStartPos+"-"; q2SlK8`QJ  
httpConnection.setRequestProperty("RANGE",sProperty); 7k<6oM1  
Utility.log(sProperty); BSyl!>G6n8  
45 \W%8  
igGg[I1?  
InputStream input = httpConnection.getInputStream(); %k+G-oT5  
//logResponseHead(httpConnection); &N+i3l6`  
eI#b%h  
He1hgJ)N  
byte[] b = new byte[1024]; tjId?}\  
int nRead; jeu|9{iTVu  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8c%Sd'+Pt  
{ LtK= nK  
nStartPos += fileAccessI.write(b,0,nRead); m ?)k&{I  
//if(nThreadID == 1) @,\J\ rb  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l(~i>iQ 4  
} ^J]_O_ee$  
/%F}vW(!  
p)k5Uh"  
Utility.log("Thread " + nThreadID + " is over!"); 9-`P\/  
bDownOver = true; e'y$X;nIv  
//nPos = fileAccessI.write (b,0,nRead); hKjG/g:#G  
} q4xP<b^  
catch(Exception e){e.printStackTrace ();} y' r I1eF  
} [t}@>@W|  
} Quts~Q  
pRez${f.(s  
m|by^40A(  
//打印回应的头信息 pl4:>4l/  
public void logResponseHead(HttpURLConnection con) Tu[I84  
{ C" 2K U*  
for(int i=1;;i++) g^mnYg5  
{ SJai<>k h  
String header=con.getHeaderFieldKey(i); ~!iZn  
if(header!=null) Acl?w }Y  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r:~q{  
Utility.log(header+" : "+con.getHeaderField(header)); +U^H`\EUr  
else V/dL-;W;  
break; ^VOA69n>$  
} -TT{4\%s  
} 1Z_2s2`p  
&W*do  
%p}xW V.  
public void splitterStop() |!?lwBs4  
{ /h v2=A  
bStop = true; .[Nr2w:>  
} k>V~ iA  
.Z9{\tj  
0Z&ua  
} j0.E!8Ae{  
G^W'mV$xl  
t4H*&U  
/* x1'4njTV$  
**FileAccess.java C9VtRq  
*//文件访问(定位,写) AcQmY?  
package NetFox; IW$qP&a  
import java.io.*; XlaGR2-%  
i[O{ M`Z%  
}9*NEU) o  
public class FileAccessI implements Serializable{ (/^dyG|X'  
3;<Vv*a"Dm  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 I*`;1+`  
RandomAccessFile oSavedFile; %c-T Gr,  
long nPos; `#c36  
JF6=0  
.:(T}\]R  
public FileAccessI() throws IOException r=4vN=:  
{ *!c&[- g  
this("",0); ,w|Or}h]7  
} x4Wu`-4^  
KGP*G BZr  
zk^uS#  
public FileAccessI(String sName,long nPos) throws IOException =}OcMM`f  
{ 3T)_(SM"  
oSavedFile = new RandomAccessFile(sName,"rw"); 5STk"  
this.nPos = nPos; {9;x\($&a  
oSavedFile.seek(nPos); 3'xmq  
} [ ;LP6n7v  
}c@duf-l  
dUc ([&  
public synchronized int write(byte[] b,int nStart,int nLen) @@=e-d  
{ 557%^)v  
int n = -1; :7L[v9'  
try{ ltg\x8w?c  
oSavedFile.write(b,nStart,nLen); z>A;|iL  
n = nLen; WCL#3uYk"  
} M}\p/r=  
catch(IOException e) K]H [A,  
{ m;oCi }fL  
e.printStackTrace (); |rL#HG  
} O3En+m~3n)  
t+t D  
qL2Sv(A Z!  
return n; D^<5gRK?  
} I/k/5  
X ApSKJ  
D&|HS!  
} v:zKn[;o  
mBON>Z [4.  
^"GDaMF  
/* Rxl/)H[Lc"  
**SiteInfoBean.java 6 vr8rJ-  
*/ nPg,(8Tt  
package NetFox; YtFH@M  
()ZP =\L  
T_I ApC  
public class SiteInfoBean { rvG0aqO `  
/?B%,$~  
|gwGCa+  
private String sSiteURL; //Site's URL >)8<d3m  
private String sFilePath; //Saved File's Path = 6.i.(L_S  
private String sFileName; //Saved File's Name WJBwo%J  
private int nSplitter; //Count of Splited Downloading File dCO7"/IHW  
>7(7  
.-?Txkwb  
public SiteInfoBean() x#jJ 0T  
{//nSplitter的缺省值为5 yGE)EBH  
//default value of nSplitter is 5 :S=!]la0h  
this("","","",5); %~EOq\&  
} ~n{lu'SIX2  
6e4A| <  
A(T=  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !~!\=etm  
{ U*cWNn:."  
sSiteURL= sURL; kPezR: 31  
sFilePath = sPath; _qU;`Q  
sFileName = sName; ~ea&1+Z[3  
this.nSplitter = nSpiltter; oA`G\Xh_E  
-5u. Ix3  
PD`EtkUnv  
} 'da$i  
Ch7&9NW  
ds:&{~7L<T  
public String getSSiteURL() .s`7n *xz  
{ 5O]eD84B  
return sSiteURL; sHm :G_  
} CW'<Nh  
4R28S]Gb  
B/gI~e0  
public void setSSiteURL(String value) JTdcL mL  
{ a8cX {6  
sSiteURL = value; C sx EN4  
} Z/+H  
22gh,e2o  
6bd{3@   
public String getSFilePath() N7#,x9+E  
{ yq,%<%+  
return sFilePath; .v[!_bk8C  
} (Z#j^}G_l  
{9|S,<9  
Q'c[yu  
public void setSFilePath(String value) /[=U$=uH  
{ m?]= =9  
sFilePath = value; drd5o Z  
} uYMH5Om+i  
=aCd,4B}  
4ad-'  
public String getSFileName() Tk:%YS;=  
{ ~NB lJULS  
return sFileName; #waK^B)<a  
} u=& $Z  
yPT\9"/  
L]3gHq  
public void setSFileName(String value) =e|  
{ %40+si3c  
sFileName = value; 9}#9i^%}  
} "fWm{;  
0s%]%2O N  
&U{"dJr  
public int getNSplitter() 'aJm4W&j  
{ /9(8ML#E  
return nSplitter; laA3v3*  
} B5MEE  
F?hGt]o  
>IEc4  
public void setNSplitter(int nCount) zD): yEc  
{ \5R>+[n!  
nSplitter = nCount; ^/"2s}+  
} 3TF'[(K=  
} W0s3nio  
p ^U#1c  
aT}?-CUxx  
/* P/ 7aj:h~P  
**Utility.java L^{wxOf&6E  
*/ {!37w[s~  
package NetFox; % QI6`@Y"  
FXo{|z3  
*>J45U(6:  
public class Utility { g<5G#  
%nT&  
_NB8>v  
public Utility() 28=L9q   
{ >|_B=<!99W  
4 k y/a1y-  
Fu"@)xw/-q  
} ;1L7+.A  
A S]jJc^  
//线程睡眠 !?J?R-C  
public static void sleep(int nSecond) 5gbD|^ij  
{ 0=c:O  
try{ 2hF j+Ay  
Thread.sleep(nSecond); /V f L(  
} ;BjJ<?^{  
catch(Exception e) [eZ'h8  
{ q\T}jF\t  
e.printStackTrace (); , \R,O  
} .q_SA-!w>  
} HFTDea+#  
TDY =!  
//日志 '^~3 8=FA  
public static void log(String sMsg) mBWhC<kKs  
{ <7yn:  
System.err.println(sMsg); sZYTpZgW4L  
} vC_O! 2E  
i=j4Wg,{J  
.p /VRlLU  
public static void log(int sMsg) +e( (!  
{ } f+hB  
System.err.println(sMsg); ,7*-%05[\  
} ~R\U1XXyUY  
} vp..>BMJ  
 Wkc^?0p  
VO+3@d:  
/* ["XS|"DM  
**TestMethod.java C^!ej"  
*/ E K#ib  
package NetFox; eVB.g@%T  
p="K4E8~H  
{uji7TB  
public class TestMethod { MD=VR(P?eq  
v m)'C C  
HK!Vd_&9,  
public TestMethod() Y~uqKb;A  
{ ///xx/weblogic60b2_win.exe v9+1[Y";  
try{ $,#,yl ol  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); J&jig?t  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); C! J6"j  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~n`G>Oe3  
fileFetch.start(); Oky9G C.a  
} 0fU^  
catch(Exception e){e.printStackTrace ();} X]AbBzy  
} P/ x@N  
"Go)t + -  
} R22P ol  
U&<w{cuA  
*r]Mn~3  
public static void main(String[] args) Ax"I$6n>  
{ XqK\'8]\Mw  
new TestMethod(); t4CI+fqy  
} PbN"+qM  
} &yQM 8J~  
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