http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Mj5&vs~n;
} eOUv#F
for(int i=0;i<nEndPos.length-1;i++) )N'rYS'9
{ d;FOmo4
nEndPos = nStartPos[i+1]; %("WoBPH`
} p%ZOLoc)Y
nEndPos[nEndPos.length-1] = nFileLength; iwx*mC{|A
} e` {F7rd:
} Nm4 h
GA+#'R
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//启动子线程 f)#rBAkt
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; P5Is#7udN8
for(int i=0;i<nStartPos.length;i++) |$+ xVi8
{ n>k1D
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4RyQ^vL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %D6HY^]ayw
nStartPos,nEndPos,i); WinwPn+9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bBg=X}9
fileSplitterFetch.start(); -?vII~a9y
} 1.IEs:(;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V<ExR@|}.%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _Y _v&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~.&PQE$DF
nEndPos = " + nFileLength); GMOnp$@H^s
// fileSplitterFetch[nPos.length-1].start(); #,B+&SK{
`PS^o#
&MJcLM]
//等待子线程结束 uRCZGg&V?#
//int count = 0; khe.+Qfgj
//是否结束while循环 JrNqS[c/
boolean breakWhile = false; 6BH P#B2j
CXd/M~:!
p,K!'\
while(!bStop) :F`"CR^,
{ `BzjDI:a
write_nPos(); :878q TB
Utility.sleep(500); K'U8ft*_
breakWhile = true; Ju"K"
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J. $U_k
for(int i=0;i<nStartPos.length;i++) cH6<'W{*
{ =O??W8u
if(!fileSplitterFetch.bDownOver) -=4{X R3
{ "1z#6vw5a
breakWhile = false; lN~u='Kc
break; h[>Puoz
} s6(bTO.
} &`I7aP|
if(breakWhile) wu~?P`
break; Btyp=wfN[
-jk-ve
d7P'c!@+
//count++; ycj\5+g
//if(count>4) \\Te\l|L
// siteStop(); WwF2Ry^a
} $0&<Jx
Nq"J[l*+g
iyTKy+3A
System.err.println("文件下载结束！"); cceh`s=cU
} JmF:8Q3H
catch(Exception e){e.printStackTrace ();} CXh>'K
} ~nRbb;M
"5@\"L
SQ-CdpT<
//获得文件长度 X}ft7;Jpy
public long getFileSize() 8;$zD]{D1
{ l?O%yf`s
int nFileLength = -1; MuF{STE>->
try{ ;( [^+_/
URL url = new URL(siteInfoBean.getSSiteURL()); zbAyYMtEk
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mGh8/Xt
httpConnection.setRequestProperty("User-Agent","NetFox"); !SdP<{[
1otE:bi
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int responseCode=httpConnection.getResponseCode(); f0"_ {\
if(responseCode>=400) #ba7r ]Xu
{ go?}M]c%7
processErrorCode(responseCode); Vc!'=&*
return -2; //-2 represent access is error b8&z~'ieR
} >D_!d@Z
@*=eqO
k-I U}|Xz
String sHeader; '}9 %12\^h
WZN0`Od
09J,!NN
for(int i=1;;i++) p%-;hL!
{ G]T&{3g-.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); oT i$@q
//Utility.log(in.readLine()); B8>3GZi
sHeader=httpConnection.getHeaderFieldKey(i); %mRnJgV5k
if(sHeader!=null) 4^7*R
{ #{5h6IC
if(sHeader.equals("Content-Length")) wRu\9H}
{ #:8V<rc^
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); l4AXjq2
break; AQD`cG
} 4F,RlKHBl
} bA07zI2
else H8h,JBg5<F
break; eA-$TSWh
} LfMN 'Cb
} j`QXl
catch(IOException e){e.printStackTrace ();} { {+:Vy
catch(Exception e){e.printStackTrace ();} TNlS2b1
&H/3@A3
wDKA1i%G
Utility.log(nFileLength); E&0]s
Q&vU|y
Z9zsvg
return nFileLength; O +Xu?W]
} C,$7fW{?
& sgzSX
y<m}dW6[\
//保存下载信息（文件指针位置） t:%u4\nZ;
private void write_nPos() OQ+kOE&
{ (t"e#b(:
try{ ZmS ]4WM<
output = new DataOutputStream(new FileOutputStream(tmpFile)); m0]Lc{
output.writeInt(nStartPos.length); 8xx2+
for(int i=0;i<nStartPos.length;i++) $u, ~183
{ T1uOp5_]B
// output.writeLong(nPos); i([|@Y=
output.writeLong(fileSplitterFetch.nStartPos); =~'y'K]
output.writeLong(fileSplitterFetch.nEndPos); 95*=&d
} ,@aF#
output.close(); ><{Lh@{
} oT9qd@uQ0:
catch(IOException e){e.printStackTrace ();} P]H4!}M
catch(Exception e){e.printStackTrace ();} a.up&g_$
} \iAs
|fPR7-
07>Iq8<mu
//读取保存的下载信息（文件指针位置） -NUA
private void read_nPos() j5m]zh5\J=
{ e84O 6K6o
try{ { P@mAw
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); W"H(HA
int nCount = input.readInt(); 4B@Ir)^(*
nStartPos = new long[nCount]; 4]no#lVRJ
nEndPos = new long[nCount]; 3u4P [
for(int i=0;i<nStartPos.length;i++) ~X,ZZ 9H
{ A5,(P$@k
nStartPos = input.readLong(); tw&biLM5T
nEndPos = input.readLong(); 3e1^r_YI
} K*N8Vpz(
input.close(); '19kP.
} oI x!?,1
catch(IOException e){e.printStackTrace ();} Xd'B0kQaT
catch(Exception e){e.printStackTrace ();} !$#8Z".{v{
} VTn6@z_ x
&W N R{
YT<(2u#Ng
private void processErrorCode(int nErrorCode) @O HsM?nW
{ kI,O9z7A7
System.err.println("Error Code : " + nErrorCode); a4eE/1
} Z"E2ZSa0
BHDd^bd
<'vtnz
//停止文件下载 S=3H.D!f
public void siteStop() <Gz*2i
{ }PzHtA,V
bStop = true; I GB)
for(int i=0;i<nStartPos.length;i++) -{Fy@$!
fileSplitterFetch.splitterStop(); (w?W=guHu
+kT o$_Wkz
[[KIuW~ot
} 2Y%E.){
} .p-T >
//负责部分文件的抓取 j\2q2_f
**FileSplitterFetch.java ig4mj47wJ
*/ ^Kn:T`vB
package NetFox; ;D}E/'=
7?2<W-n
PRN%4G
import java.io.*; K(Ak+&[
import java.net.*; TTz_w-68
KHoDD=O
$%"~.L4
public class FileSplitterFetch extends Thread { =5#sB*
MzIn~[\
7z3YzQ=Kg
String sURL; //File URL 'Jl73#3
long nStartPos; //File Snippet Start Position +EM^
long nEndPos; //File Snippet End Position B{cb'\C
int nThreadID; //Thread's ID xU'% 6/G
boolean bDownOver = false; //Downing is over W4:#=.m
boolean bStop = false; //Stop identical ^qV6khg
FileAccessI fileAccessI = null; //File Access interface ^zR*s |1Q
I|)U>bV
B q7Qbj
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException SHN'$f0Mb
{ W.TdhJW9
this.sURL = sURL; I5w>*F
this.nStartPos = nStart; Cm#[$T@C
this.nEndPos = nEnd; w~WW2w
nThreadID = id; LRv[,]b
fileAccessI = new FileAccessI(sName,nStartPos);//定位 rY]QTS">o
} <xr\1VjA
,\D*=5
xRm~a-rp
public void run() $ 1v'CT
{ xoN?[
while(nStartPos < nEndPos && !bStop) 9v(k<('_
{ 6>F]Z)]}
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Yk yB
try{ SJ8|~,vL
URL url = new URL(sURL); N6%M+R/Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YF<U'EVU-
httpConnection.setRequestProperty("User-Agent","NetFox"); >d$Sh`a6
String sProperty = "bytes="+nStartPos+"-"; |Q*{yvfEo
httpConnection.setRequestProperty("RANGE",sProperty); L'<.#(|
Utility.log(sProperty); T&s}~S=m
9M1UkS$`@
Q ;$NDYV1
InputStream input = httpConnection.getInputStream(); zfm#yDf
//logResponseHead(httpConnection); aui3Mq#f
#iP5@:!Wm~
9Vtn62+
byte[] b = new byte[1024]; c_FnJ_++f
int nRead; kr>F=|R]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Hjc *WTu
{ Qk`LBvg1
nStartPos += fileAccessI.write(b,0,nRead); "UTAh6[3oD
//if(nThreadID == 1) nsyeid*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,nz3S5~
} ,_RPy2N
tqicyNL
P2sM3C
Utility.log("Thread " + nThreadID + " is over!"); FmC [u
bDownOver = true; 4?.L+wL
//nPos = fileAccessI.write (b,0,nRead); _A,mY6*
} y~;w`5;|
catch(Exception e){e.printStackTrace ();} Gc{s?rB_
} SX@zDuM
} @V qI+5TA
@&GfCg5Cb
]6z ; M;F`
//打印回应的头信息 Vl%jpjqP
public void logResponseHead(HttpURLConnection con) p _q]Rt
{ _e94
for(int i=1;;i++) C!6d`|
{ = `oGH
String header=con.getHeaderFieldKey(i); zM!2JC
if(header!=null) H:_R[u4r
//responseHeaders.put(header,httpConnection.getHeaderField(header)); N_| '`]D
Utility.log(header+" : "+con.getHeaderField(header)); DE" Y(;S
else >!%F$$
break; 9y(491"o
} !TeI Jm/l
} dI) 9@UL
4$_:a?9
^Bu55q
public void splitterStop() ~dlpoT
{ %rq/&#jC
bStop = true; L}\~)
} 8N9X1Mb|
g<PglRr"
`F4gal^ ^
} vmIt!x
E>Lgf&R#W
H?tX^HO:q
/* ^~K[bFbW
**FileAccess.java go B'C
*//文件访问(定位，写) SCo;Ek
package NetFox; O7lFg;9c`
import java.io.*; L{Kl!
?yy,3:
p^*A&7d:P
public class FileAccessI implements Serializable{ V3c7F4\
^b^}6L'Z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 vfloha p
RandomAccessFile oSavedFile; p d(W(-`8!
long nPos; QZv}\C-c
y87oW_"h
5Sx.'o$
public FileAccessI() throws IOException P9jPdls
{ +~f=L- >
this("",0); 2VaKt4+`
} (Fs{~4T
dq^vK
)>I-j$%=2
public FileAccessI(String sName,long nPos) throws IOException e"&QQ-q
{ {.o@XP,.
oSavedFile = new RandomAccessFile(sName,"rw"); 5[Uv%A?H#_
this.nPos = nPos; v:?l C<,
oSavedFile.seek(nPos); ]8CgHT[^7
} d;.H9Ne
'^%kTNn
]-cSTtO
public synchronized int write(byte[] b,int nStart,int nLen) JsHD3
{ DTvCx6:!
int n = -1; p> g[: ~
try{ fi [4F
oSavedFile.write(b,nStart,nLen); %uDH_J|^
n = nLen; v"-K-AQjB
} 7> 8L%(7
catch(IOException e) Z7p!YTA
{ a!B"WNb+
e.printStackTrace (); _ o.j({S
} 8p_6RvG
}/2M?W0
CD[}|N
return n; e%C_>
} Y`rli
||4T*B06
i!EAs`$o`
} qKTzigjj
-tfUkGdx;l
-ARks_\
/* \3`r/,wY
**SiteInfoBean.java zPN:)
*/ wKKQAM6P1
package NetFox; us+z8Mz
|Wr$5r
k$ b)
public class SiteInfoBean { q _Z+H4
hLj7i?
" =6kH,
private String sSiteURL; //Site's URL */2nh%>$
private String sFilePath; //Saved File's Path a|#TnSk
private String sFileName; //Saved File's Name 8N \<o7t%
private int nSplitter; //Count of Splited Downloading File N(V_P[]"*,
F^81?Fi.
pQ>|dH+.
public SiteInfoBean() N'i)s{'
{//nSplitter的缺省值为5 2T(7V[C%9
//default value of nSplitter is 5 dz!m8D0
this("","","",5); G.`},c;A-
} sNM ]bei
PQp/&D4K
w!'y,yb%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) t<o7 S:a"
{ .f"1(J8
sSiteURL= sURL; uehu\umt=
sFilePath = sPath; huW,kk<]y
sFileName = sName; 7hTpjox2
this.nSplitter = nSpiltter; ~6IY4']m*
OTl9MwW
*jvP4Nz)k
} "blq)qo)
p]ujip
;dPaWS1D
public String getSSiteURL() lX.-qCV"B
{ h8X[*Wme
return sSiteURL; at4JLbk
} >]8(3&zd
~(8fUob
` Nf
public void setSSiteURL(String value) ="v`W'Pd
{ 8|^&~Rl4
sSiteURL = value; {Wi*B(
} ]YtN6Rq/
4wkv#vi7!-
x;<0Gg~jB
public String getSFilePath() `hdff0
{ OTE,OCB[
return sFilePath; ZuybjV1/f6
} ;i\N!T{>
)z\#
3E^qh03(
public void setSFilePath(String value) Ar[|M2|
{ Qrt\bz h/}
sFilePath = value; qZ'2M.;
} }dpTR9j=
Hy1$Kvub
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public String getSFileName() >$TvCw
{ :L@n(buRN
return sFileName; <D3mt Q
} q&J5(9]O|L
>~nr,V.q
^8_yJ=~V
public void setSFileName(String value) Ln2FG4{
{ |Y05 *!\P*
sFileName = value; |Q%P4S"B?
} }6!/Nb
qFwt^w
p]EugLEmG
public int getNSplitter() >h)kbsSU0z
{ !p).3Kx0
return nSplitter; Rx&O}>"E>l
} >5#}/G&
r'j88)^
IHdA2d?.]
public void setNSplitter(int nCount) ^!\AT!OT
{ N|$9v{ j_
nSplitter = nCount; L7;~4_M9.V
} Bh'fkW3
} Q5T3
!#_2 ![
l[c '%M|N
/* 't}\U&L.{
**Utility.java p|.5;)%|
*/ y;Cs#eo
package NetFox; V%s7*`U
:\P@c(c{^C
ioD8-
public class Utility { <+g77NL
X':FFD4h
pT->qQ3;
public Utility() 4h@,hY1#
{ pQBn8H|Y
(O4oIU
&{.IUg
} K~vJ/9"|R
cVW7I
//线程睡眠 qsp.`9!
public static void sleep(int nSecond) wDh]vH[
{ ;&O?4?@4
try{ ah:["< z<
Thread.sleep(nSecond); u_$4xNmQ
} yy8-t2V
catch(Exception e) hg" i;I
{ f(w>(1&/B
e.printStackTrace (); O*l,&5
} ^#<L!yo^
} GNMOHqg4
qx5`lm~L
//日志 5<dg@,\
public static void log(String sMsg) 8F8?1
{ /RJ
System.err.println(sMsg); _x<NGIz
} BA:x*(%~
hz4?ku
6]b"n'G
public static void log(int sMsg) Pl/ dUt_
{ VQHB}Y@^
System.err.println(sMsg); _GG\SWm
} s)]jX
} xKSQz
J;>epM;*
}4YzP 4
/* 7yfh4-1M
**TestMethod.java ?"9h-g3`x}
*/ !.,wg'\P
package NetFox; D8wf`RUt
Dm}eX:'{
XG.[C>
public class TestMethod { T"z<D+pN
pr#%VM[':R
gPKf8{#%e
public TestMethod() o4kLgY !Q
{ ///xx/weblogic60b2_win.exe RhE~Rwbx
try{ t<##0#xS.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Qjfgxy]
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); le'RU1k
SiteFileFetch fileFetch = new SiteFileFetch(bean); }N[X<9^Z
fileFetch.start(); _cs(f<>oCO
} \ZLi Y
catch(Exception e){e.printStackTrace ();} O%T?+1E
VC88re`
^y/Es2A#t
} q~R8<G%YK
$IE}fgA@5
0P5VbDv$r7
public static void main(String[] args) =PRQ3/?5
{ = J;I5:J
new TestMethod(); c#N4XsG,
} 4{uQ}ea
} N55F5
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