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)); .JX9(#Uk
} DhD^w;f]
for(int i=0;i<nEndPos.length-1;i++) D";@)\jN
{ ^]MLEr!S
nEndPos = nStartPos[i+1]; ~DP_1V?
} ZY=a[K
nEndPos[nEndPos.length-1] = nFileLength; tr|)+~x3
} _)[UartKx
} 3@\J#mR
#jM-XK
Bu"5NB
//启动子线程 P7\?WN$p
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; .FC|~Z1T<F
for(int i=0;i<nStartPos.length;i++) \IZY\WU}2
{ IR|#]en
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vKBijmE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3<HZ)w^B
nStartPos,nEndPos,i); n50WHlMtt
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); :B:6ezDF6
fileSplitterFetch.start(); SM\qd4
} i>e?$H,/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %S/?Ci
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1P?|.W_^1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Z}S7%m
nEndPos = " + nFileLength); H{hzw&dZ<P
// fileSplitterFetch[nPos.length-1].start(); YO9;NA{sH
_$i)bJ
&yG5w4<
//等待子线程结束 ^09-SUl^
//int count = 0; Q2[;H!"
//是否结束while循环 yt<h!k$ _P
boolean breakWhile = false; +`tk LvM
Q)im2o@z
|enb5b78
while(!bStop) zPN:)
{ Raf(m,o(
write_nPos(); -\n%K
Utility.sleep(500); %`*On~
breakWhile = true; quRTA"!E
K/K|[=bl
@Gt.J*!s/
for(int i=0;i<nStartPos.length;i++) psUT2
{ \,pObWm
if(!fileSplitterFetch.bDownOver) 'qJ0338d#U
{ \rd%$hci
breakWhile = false; e~7FK_y#0
break; r1:CHIwK
} j4I ~
} 3OFI>x,h
if(breakWhile) bEln.)
break; o59b#9
KwU;+=_.
SEVB.;
//count++; \440gH`
//if(count>4) h"nhDART<
// siteStop(); R3%%;`c=
} Jj?HOtaM
O]'2<;
RL3*fRlb
System.err.println("文件下载结束！"); %SuELm
} y%?'<j
catch(Exception e){e.printStackTrace ();} p6!5}dD(
} `aTw!QBfG
[:uHe#L
sUU[QP-
//获得文件长度 %%NT m
public long getFileSize() `]^W#6l
{ n'0r (
int nFileLength = -1; .f"1(J8
try{ [S1 b\f#
URL url = new URL(siteInfoBean.getSSiteURL()); \*[DR R0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); huW,kk<]y
httpConnection.setRequestProperty("User-Agent","NetFox"); `jSegG'
p6V#!5Q
~6IY4']m*
int responseCode=httpConnection.getResponseCode(); ;wkMa;%`g|
if(responseCode>=400) k7j.VpN9
{ *jvP4Nz)k
processErrorCode(responseCode); |1zfXG,R
return -2; //-2 represent access is error FPH2dN
} p]ujip
(;&}\OX6nm
KIp^| k7>
String sHeader; '~ H`Ffd.
3dlY_z=0
DQ30\b"gU
for(int i=1;;i++) Q6D>(H#"0
{ ,H%[R+)
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {2YqEX-I*
//Utility.log(in.readLine()); %}e['d h
sHeader=httpConnection.getHeaderFieldKey(i); r8?p6E
if(sHeader!=null) 1wFW&|>1
{ S~)`{ \
if(sHeader.equals("Content-Length")) 6VVxpDAi:
{ (Gw*xsn1
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); TgaxZW
break; Je,o(:
} y0`; br\X
} ;0Q" [[J
else ,n[<[tkCR
break; *5.wwV
} 1y\bJ
} 3&CV!+z
catch(IOException e){e.printStackTrace ();} :;eQ*{ `\
catch(Exception e){e.printStackTrace ();} WMC\J(@.
T0Xm}i
;i\N!T{>
Utility.log(nFileLength); ^2);*X>
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L9N}lH
return nFileLength; n}_}#(a
} 2Z%n "z68
-gm5Eqi
-fXQ62:S
//保存下载信息（文件指针位置） 9!(%Vf>
private void write_nPos() }dpTR9j=
{ !y B4;f$
try{ K4jHha
output = new DataOutputStream(new FileOutputStream(tmpFile)); &a=78Z
output.writeInt(nStartPos.length); R?{xs
for(int i=0;i<nStartPos.length;i++) kmX9)TMVO
{ 2]Il:>n,
// output.writeLong(nPos); tcT=a@
output.writeLong(fileSplitterFetch.nStartPos); '(rD8 pc
output.writeLong(fileSplitterFetch.nEndPos); R~T}
} _dRB=bl"O
output.close(); vi *A5
} G{]RC^Zo
catch(IOException e){e.printStackTrace ();} Jx~H4y=z
catch(Exception e){e.printStackTrace ();} jLM([t
} l)*(UZ"
&R?`QB2/
l cHf\~
//读取保存的下载信息（文件指针位置） ZnRT$ l O
private void read_nPos() >mX6;6FF
{ 5{oc
try{ }oA>0Nw$K
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); JRw,${W
int nCount = input.readInt(); KILX?Pt[7
nStartPos = new long[nCount]; !p).3Kx0
nEndPos = new long[nCount]; eG1V:%3
for(int i=0;i<nStartPos.length;i++) `WN80d\)&
{ `MCiybl,&P
nStartPos = input.readLong(); X!K>.r_Dg
nEndPos = input.readLong(); \fUX_0k9,
} Te L&6F$
input.close(); 1P(=0\P>&
} ~HhB@G!3
catch(IOException e){e.printStackTrace ();} #Zw:&' QB
catch(Exception e){e.printStackTrace ();} $BMXjXd}
} :MY=Q]l
Y|Q(JX
Fz';H
private void processErrorCode(int nErrorCode) OPDT:e86Y=
{ o+&Om~W
System.err.println("Error Code : " + nErrorCode); 8 5X}CCQ
} <O 0Q]`i
Ao8ua|:
/nQuM05*Z
//停止文件下载 ~Ym_ {
public void siteStop() {%G9iOV.
{ XDJE]2^52?
bStop = true; e|!'
for(int i=0;i<nStartPos.length;i++) EN\cwa#FU
fileSplitterFetch.splitterStop(); )gdLb}
(Fon!_$:
zP%s]>hH
} BP@tI|
} wQUl!s7M;
//负责部分文件的抓取 FHQ`T\fC$@
**FileSplitterFetch.java B6 (\1
*/ 3 R+e
package NetFox; 8#yu.\N.xt
&>,]YrU
d<7b<f"~
import java.io.*; ?-<lIFFh
import java.net.*; m%`YAD@2z
jeWv~JA%L|
&|{1Ws
public class FileSplitterFetch extends Thread { rZ `1G
ih".y3
^#<L!yo^
String sURL; //File URL {\D&*
long nStartPos; //File Snippet Start Position KJ'ID
long nEndPos; //File Snippet End Position qx5`lm~L
int nThreadID; //Thread's ID i`2SebDj'w
boolean bDownOver = false; //Downing is over c%/b*nQ(=
boolean bStop = false; //Stop identical >|A,rE^Ojt
FileAccessI fileAccessI = null; //File Access interface S[3"?$3S
,~naKd.ZY
g=$U&Hgs
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8xO
{ \,G9'c 'u
this.sURL = sURL; 1;$XX#7o
this.nStartPos = nStart; aYaEy(m
this.nEndPos = nEnd; N9_* {HOy
nThreadID = id; =WT$\KYGv
fileAccessI = new FileAccessI(sName,nStartPos);//定位 L T$U z
} uL/wV~g
~Mn3ADIb=
bwXeEA@{
public void run() X6G{.Vh"
{ ]qT&6:;-]
while(nStartPos < nEndPos && !bStop) U<w8jVE
{ HKrENk
s;9Du|0f^
=4eJ@EVM
try{ 6P{^j
URL url = new URL(sURL); ?Tc#[B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :E.a.-
httpConnection.setRequestProperty("User-Agent","NetFox"); !.,wg'\P
String sProperty = "bytes="+nStartPos+"-"; Njg$~30
httpConnection.setRequestProperty("RANGE",sProperty); BS##nS-[
Utility.log(sProperty); Dm}eX:'{
^<OYW|q?\r
\~hrS/$[$
InputStream input = httpConnection.getInputStream(); rpRyB9
//logResponseHead(httpConnection); v;<gCzqQh
5U~KYy^v
hi[nUG(OI
byte[] b = new byte[1024]; '|SO7}`;Q
int nRead; VhkM{O
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) nXRa_M(z8
{ L5FOlzn
nStartPos += fileAccessI.write(b,0,nRead); >4X2uNbZS
//if(nThreadID == 1) |ky40[C
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "sN%S's
} $CEdJ+0z
cb9-~*1
4]U=Y>\Sr
Utility.log("Thread " + nThreadID + " is over!"); _cs(f<>oCO
bDownOver = true; T o["o!(;z
//nPos = fileAccessI.write (b,0,nRead); }d?;kt
} XvaIOt>A
catch(Exception e){e.printStackTrace ();} }i~k:kmV
} 1<BKTMBq?{
} Dds-;9
K'ZNIRr/C
M 5sk&>
//打印回应的头信息 [LnPV2@e
public void logResponseHead(HttpURLConnection con) Vn^GJ'^
{ 0P5VbDv$r7
for(int i=1;;i++) 1c0'i
{ X,v.1#[
String header=con.getHeaderFieldKey(i); = J;I5:J
if(header!=null) x 7by|G(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); z{L'7
Utility.log(header+" : "+con.getHeaderField(header)); 4{uQ}ea
else =-si| 1Z
break; Nbpn"*L,
} t<Acq07
} e3 v^j$
72sqt5C]
2o?j{K
public void splitterStop() U80=f2
{ ,j*9)
bStop = true; i=Qy?aU?
} /qIQE&V-
|_TiF;^
> ubq{'
} 7\ _MA!:<
f7_(C0d
?y-^Fq|h
/* TGF$zvd
**FileAccess.java [K3 te
*//文件访问(定位，写) s>J5.Z7"'j
package NetFox; -MTk9<qnT
import java.io.*; F$as#.7FF
X hq ss),
;|Mfq`s
public class FileAccessI implements Serializable{ QOXo(S
ni?k' \\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;A,X,f
RandomAccessFile oSavedFile; T>B'T3or
long nPos; =VD],R)
>_2~uF@pb
n&:ohOH%
public FileAccessI() throws IOException qk<jvha
{ bSsg`
this("",0); "&2 F
} AmF[#)90P
vu+g65"
Ah2 {kK
public FileAccessI(String sName,long nPos) throws IOException &gp&i?%X9b
{ i{6&/TBnr
oSavedFile = new RandomAccessFile(sName,"rw"); Q7aPW\-
this.nPos = nPos; Jo {:]:
oSavedFile.seek(nPos); r'*$'QY-N
} w7@`:W
N#ggT9>X
B.; qvuM~
public synchronized int write(byte[] b,int nStart,int nLen) H'k}/<%Q
{ \n[kzi7
int n = -1; j,j|'7J%
try{ "TA0--6
oSavedFile.write(b,nStart,nLen); LaQ7A,]
n = nLen; h+W$\T)
} 'f6H#V*C
catch(IOException e) ^bv^&V&IB
{ q-`&C
e.printStackTrace (); SZKYq8ZA)V
} ~,}|~
lbAhP+B
Fx:38Ae
return n; 9G/!18 X?f
} w0~%,S
@R5^J{T
fbh,V%t7
} O>h`
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%M iv8
/* ,-Hj
**SiteInfoBean.java >/A]C$?3
*/ hoq2zDjD
package NetFox; c& ;@i$X(
..JRtuM-v
U823q-x
public class SiteInfoBean { :i<*~0r<
zP,r,ok7
4k225~GQ:C
private String sSiteURL; //Site's URL !mxH/{+|n
private String sFilePath; //Saved File's Path BEOPZ[Q|c
private String sFileName; //Saved File's Name hWy@?r.
private int nSplitter; //Count of Splited Downloading File lEHx/#qt9
*6?mZ*GYY
i"<W6
public SiteInfoBean() (\F9_y,6*\
{//nSplitter的缺省值为5 v.|#^A?Qx
//default value of nSplitter is 5 8%K{lg"
this("","","",5); ~z:]rgX
} LFax$CZc
VO0:4{-
J9[7AiEd(/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;].X;Ky<
{ {5Bj*m5
sSiteURL= sURL; q}t]lD %C
sFilePath = sPath; @:?[R&`
sFileName = sName; d^=)n-!T
this.nSplitter = nSpiltter; KA?}o^-F
86{>X5+
j,i9,oF6]
} vxZ'-&;t
V[(fE=cIN~
'W(u.
public String getSSiteURL() xq((]5Py
{ GURiW42
return sSiteURL; NF&Sv
} ~LS</_N
iE''>Z
T_S3_-|{==
public void setSSiteURL(String value) v*!N}1+J
{ zcP=+Y)YA
sSiteURL = value; c]uieig0~
} tpGT~Y(
ye.6tlW
%C/p+Tg
public String getSFilePath() #%[;vK
{ Fl_}Auj{&(
return sFilePath; fn,n'E]
} \x-2qlZ
D\THe-Vtr
zpwoK&T+
public void setSFilePath(String value) {d.z/Buu
{ r0}x:{$M
sFilePath = value; ,1{qZ(l1
} a]r+np]vTy
t)&U'^
3Z";a
public String getSFileName() ?+Gt?-! 5q
{ RxqNgun@
return sFileName; )c4tGT<
} YD[HBF)~j
j1;[6XG
` Tap0V
public void setSFileName(String value) tBGLEeL/.
{ `TPIc
sFileName = value; U\P4ts
} v^ ^Ibv
bW=q G
i9L]h69r
public int getNSplitter() 4z(~)#'^
{ X\m\yv}}
return nSplitter; /F;2wT;
} &ww-t..
xfeED^?
W\~ie}D{
public void setNSplitter(int nCount) Q2 !GWz$
{ f5*qlQJFz\
nSplitter = nCount; CK[8y&
} EsKgS\`RZ
} hV(^Y)f
Z;G*wM"
NVx>^5QV
/* @/^<9
**Utility.java C$[iduS
*/ $0 .6No_|
package NetFox; W^8
d` ttWWPw
h,$CJdDY]
public class Utility { q~}oU5
Tv"T+!Z
UDI\o1Rbp
public Utility() $_F_%m"\
{ i?!9%U!z4
b,+Sa\j)(
+%XByY5
} 1Rd|P<y
@ ;!IPiU
//线程睡眠 HX2u{2$
public static void sleep(int nSecond) *F%1~
{ ?^Aj\z>
try{ :2KHiT5
Thread.sleep(nSecond); =H)]HxEEM
} d'96$e o~
catch(Exception e) /''=V.-N
{ f!kZyD7
e.printStackTrace (); '!^7 *@z
} 2L&c91=wE
} lW?}Ts~'
q7lC}'2fu
//日志 _G'ki.[S7
public static void log(String sMsg) 82@^vX
{ ?7Cm+J
System.err.println(sMsg); rx9*/Q0F
} p(pfJ^/:(
PV#h_X<l%
B6dU6"
public static void log(int sMsg) Xr K29a
{ ^<!R%"o-
System.err.println(sMsg); ULt5Zi
} / ]8e[t>!f
} ?TpjU*Cxy
2FuV%\p
/}6I3n
/* B/l^=u+-
**TestMethod.java n,FyK`x
*/ o:{Sws(=
package NetFox; `"65 _?B i
^"7-`<J
8p 4[:M@
public class TestMethod { 1*p6UR&
%JBLp xnq
ta{24{?M\
public TestMethod() eOb--@~8
{ ///xx/weblogic60b2_win.exe N*36rR$^
try{ _]5UuIMl
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -]^JaQw
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); n5C,Z!)z
SiteFileFetch fileFetch = new SiteFileFetch(bean); /!0&b?
fileFetch.start(); Xb:* KeZq
} kKlNhP(
catch(Exception e){e.printStackTrace ();} OvT[JpV
:lXY% [!6P
~TH4='4W3
} MDytA0M
MxpAh<u!vF
R|*0_!O:[
public static void main(String[] args) CtMqE+j^
{ h F+aL
new TestMethod(); #~'d Y\&
} #qVTB@d
} 9@CRL=
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