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)); fuUtM_11
} .4WJk>g
for(int i=0;i<nEndPos.length-1;i++) T*C25l;w
{ 4y7_P0}:B
nEndPos = nStartPos[i+1]; -]zb3P
} nD*iSb*
nEndPos[nEndPos.length-1] = nFileLength; uWdF7|PN7
} 04|ZwX$>+
} <.4(#Ebd
Bgc]t
<F0^+Pf/
//启动子线程 >;c);|'}q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [q[37;ZEQ
for(int i=0;i<nStartPos.length;i++) H"AL@=
{ ")uKDq
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9!Mh(KtQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (=7"zECq#
nStartPos,nEndPos,i); -\?-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xWzybuLp
fileSplitterFetch.start(); m- <y|3
} 66eJp-5e8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K}@rte
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); r]p3DQ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !9/`PcNIpy
nEndPos = " + nFileLength); QNMZR
// fileSplitterFetch[nPos.length-1].start(); <>\|hno}
%`5(SC].
raPOF6-_rH
//等待子线程结束 tpcB}HUv
//int count = 0; J Ah!#S(
//是否结束while循环 Zc~7R`v7}
boolean breakWhile = false; OU,FU@6,7w
X<;.
d0I s|Gs
while(!bStop) p)/e;q^
{ ?{f6su@rW
write_nPos(); o1(;"5MM
Utility.sleep(500); '1b 1N5~
breakWhile = true; jC>ZMy8U)4
X13+n2^8]
n~yKq"^
for(int i=0;i<nStartPos.length;i++) $"/l*H\h
{ >EJ{ *
if(!fileSplitterFetch.bDownOver) KUZi3\p9W>
{ wCLniCt
breakWhile = false; I8J>>H'#A
break; H;nzo3x
} (t@)`N{
} *Sj)9mp
if(breakWhile) u$%C`v>
break; :;eOhZ=_
kb2C9<
c%doNY9Q
//count++; ^vd$j-kjTP
//if(count>4) u9S*2'
// siteStop(); }=bzUA`C
} jD S\
iw,uwh|L
G^)]FwTs
System.err.println("文件下载结束！"); a^J(TW/
} ]C,j80+pK
catch(Exception e){e.printStackTrace ();} }VJ>}i*
} ,g7O
(]'wQ4iQ
tB>!1}v
//获得文件长度 z]8Mv(eL
public long getFileSize() JE9v+a{7
{ ZNw|5u^N
int nFileLength = -1; )m7%cyfC
try{ D|ze0A@
URL url = new URL(siteInfoBean.getSSiteURL()); o!UB x<4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !I?C8)
httpConnection.setRequestProperty("User-Agent","NetFox"); 2: gh q
-"nkC
mU4(MjP?
int responseCode=httpConnection.getResponseCode(); c.]QIIdK
if(responseCode>=400) A2ye ^<-C.
{ BGibBF^
processErrorCode(responseCode); H I|a88
return -2; //-2 represent access is error aYa`ex
} F!#)l*OX;
=H;n$ -P
i_*yS+Z;
String sHeader; E6~VHQa2?
bDWLHdu a
6Z#Nh@!+C
for(int i=1;;i++) ~Re4zU
{ Fc`IRPW<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 'Jf LTG.
//Utility.log(in.readLine()); n+=qT$w)
sHeader=httpConnection.getHeaderFieldKey(i); $;Fx Zkp
if(sHeader!=null) Xf&YcHo
{ X:Z3R0
if(sHeader.equals("Content-Length")) eWv:wNouk
{ QoxYzln
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,HDhP
break; x]wi&
} `e'wWV
} yGtTD9j
else FA-cTF[,(
break; K]$PRg1|3
} ||X3g"2W9
} V6dq8Z"h
catch(IOException e){e.printStackTrace ();} y$7Ys:R~
catch(Exception e){e.printStackTrace ();} %_s)Gw&sq
ZJs~,Q
,4"N7_!7
Utility.log(nFileLength); ^?Xs!kJP
e+BZoK ^
n! 5(Z5=
return nFileLength; A-4;$ QSm
} 9RlJf=Z#H
%|H]T]s
O MQ?*^eA
//保存下载信息（文件指针位置） )=GPhC/sw
private void write_nPos() u=nd7:bv
{ K.QSt
try{ QD%xmP
output = new DataOutputStream(new FileOutputStream(tmpFile)); 4$VDJ
output.writeInt(nStartPos.length); 5OWyxO3{
for(int i=0;i<nStartPos.length;i++) )e0kr46
{ BmpAH}%T
// output.writeLong(nPos); "v?F4&\ 8
output.writeLong(fileSplitterFetch.nStartPos); o7E|wS
output.writeLong(fileSplitterFetch.nEndPos); P,pC Z+H
} Rnwm6nu
output.close(); '-A;B.GV%
} 5XX)8gAo
catch(IOException e){e.printStackTrace ();} >6Uc|D
catch(Exception e){e.printStackTrace ();} L,A+"
} JqO1 a?H
FLG"c690
BJ5MCb.w
//读取保存的下载信息（文件指针位置） A^).i_&#
private void read_nPos() '8)kFR^9
{ 8'@5X-nD
try{ =M-=94
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); vzs4tkG
int nCount = input.readInt(); fWJpy#/^*K
nStartPos = new long[nCount]; OcV,pJ
nEndPos = new long[nCount]; KS(H_&j
for(int i=0;i<nStartPos.length;i++) AjEy@/
{ ( y!o
nStartPos = input.readLong(); TsT5BC63
nEndPos = input.readLong(); 1LS1 ZY
} G8vDy1`q6
input.close(); G 3U[)("
} w.58=Pr
catch(IOException e){e.printStackTrace ();} 'MW%\W;
catch(Exception e){e.printStackTrace ();} M *w{PjU
} ( gg )?
;8PO}{rD
,*W~M&n"m
private void processErrorCode(int nErrorCode) ,&@GxiU
{ *_I`{9~'
System.err.println("Error Code : " + nErrorCode); %`k [xz
} AR( gI]1
`l'T/F\
o#6QwbU25
//停止文件下载 |HT7m5tu4
public void siteStop() &Cb,C+q
{ M7?ktK9`ma
bStop = true; P6kDtUXF
for(int i=0;i<nStartPos.length;i++) h=`$ec
fileSplitterFetch.splitterStop(); 'i$._Tx
BAXu\a-C_
(/$-2.@
} P^"RH&ZQJ
} J|{50?S{^
//负责部分文件的抓取 t* Ct*
**FileSplitterFetch.java "XxmiK
*/ c6 &k?Puy
package NetFox; @4UX~=:686
;MNUT,U
n*$g1HG6
import java.io.*; /UK?&+1qE
import java.net.*; +&)/dHbL`]
#z>I =gl
Pa0W|q#?X
public class FileSplitterFetch extends Thread { k%gj
TaSS) n
c&wg`1{Hal
String sURL; //File URL }=v4(M`%
long nStartPos; //File Snippet Start Position ~vt*%GN3
long nEndPos; //File Snippet End Position w( SY
int nThreadID; //Thread's ID YK{J"Kof
boolean bDownOver = false; //Downing is over 'cc8xC
boolean bStop = false; //Stop identical 7+f6?
FileAccessI fileAccessI = null; //File Access interface wipl5O@L
R.WB.FP
oS$7k3s fj
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :(ql=+vDb4
{ _+9i
this.sURL = sURL; |U1 [R\X
this.nStartPos = nStart; A z@@0
this.nEndPos = nEnd; -h7ssf'u[
nThreadID = id; ]QR]#[Tn'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 b#N P*L&
} #tA9`!
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{+#{Cha
public void run() V0{#q/q
{ +`wr{kB$~
while(nStartPos < nEndPos && !bStop) UfPB-EFl$D
{ k0=!%f_G!
WqefH{PB
+o4o!;E)
try{ TYD( 6N
URL url = new URL(sURL); bC+ZR{M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #!z-)[S.+
httpConnection.setRequestProperty("User-Agent","NetFox"); E8Kk)7
String sProperty = "bytes="+nStartPos+"-"; y "+'4:_
httpConnection.setRequestProperty("RANGE",sProperty); j;uUM6
Utility.log(sProperty); `q]' ^EzJ
@mZK[*Ak<*
oy jkk
InputStream input = httpConnection.getInputStream(); j?*n@'
//logResponseHead(httpConnection); `:7r5}(^
kM4z %
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byte[] b = new byte[1024]; X=-=z5
int nRead; H0inU+Ih
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) PTe$dPB
{ MkFWZ9c3
nStartPos += fileAccessI.write(b,0,nRead); 3HXeBW
//if(nThreadID == 1) V<|N}8{Z2a
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZiY2N*,VO
} 7Z:3xb&>
9\?&u_ U"
p*jU)@a0
Utility.log("Thread " + nThreadID + " is over!"); $]#8D>E&
bDownOver = true; N)cODy([
//nPos = fileAccessI.write (b,0,nRead); T_2'=7
} 3(J>aQZuI
catch(Exception e){e.printStackTrace ();} vcy1itY
} 7Fpa%N/WL
} EwG+' nlE
?MSZO]Q4+
HLz<C
//打印回应的头信息 ha|2u(4
public void logResponseHead(HttpURLConnection con) X~m57bj
{ :CM-I_6
for(int i=1;;i++) 9$v\D3<Z
{ *-]k([wV
String header=con.getHeaderFieldKey(i); i| cA)
if(header!=null) =.S2gO >
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2u_=i$xW
Utility.log(header+" : "+con.getHeaderField(header)); gYbvCs8O!
else _5n2'\] H`
break; FEhBhv|m
} rMWvW(@@D
} }` `oojz
PT,*KYF_O"
,e$RvFB
public void splitterStop() <hy!B4
{ 8bMw.u=F
bStop = true; JfJ ln[
} }mp`!7?>O
PJKY$s.
@Z$fEG)9
} pHVDug3
o(v`
Z{(Gib~{N
/* !^L}LtqHI
**FileAccess.java as3uz
*//文件访问(定位，写) _d~GY,WTdO
package NetFox; |:(BI5&S
import java.io.*; k(>J?\iNW
PNLlJlYlP
H"pYj
public class FileAccessI implements Serializable{ }T902RL0
/:A239=+?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Yy[=E\z
RandomAccessFile oSavedFile; ^+~$eg&js
long nPos; y'f-4E<
"AJ>pU3
`$ bQ8$+Ci
public FileAccessI() throws IOException jc6~V$3
{ nC/T$ #G
this("",0); \K9Y@jnr
} X+emJ&Z$@
'%Oo1:wJ
$?: -A
public FileAccessI(String sName,long nPos) throws IOException RToX[R;1E
{ 0=`aXb-
oSavedFile = new RandomAccessFile(sName,"rw"); z}5'TV=^
this.nPos = nPos; 0_y&9Te
oSavedFile.seek(nPos); PK?}hz
} P'_ aNU
xop\W4s_
`,GFiTPd
public synchronized int write(byte[] b,int nStart,int nLen) K24y;968
{ Q4ii25]*
int n = -1; IP !zg|c,
try{ /Jk.b/t.*S
oSavedFile.write(b,nStart,nLen); QKz2ONV=)
n = nLen; $\4Or
} z5:3.+M5
catch(IOException e) 6x;"T+BSSS
{ ?1]B(V9nBq
e.printStackTrace (); ,aWfGh#$
} nYRD>S?uz
`n|k+tsC
0\$Lnwp_
return n; :]C\DUBo
} [MC}zd'/
8^-g yx'
9D%~~~ %b
} Q"xDRQA
Yic'p0< ?V
-IV-"-6(
/* AQ.q?'vE)
**SiteInfoBean.java 0XIrEwm@%
*/ gAi}"};
package NetFox; r:^`005
Yu^}
v g tJ+GjN
public class SiteInfoBean { [iSLn3XXRX
x~yd/ R
S 1Ji\
private String sSiteURL; //Site's URL 1 gRR
private String sFilePath; //Saved File's Path .fW`/BXE
private String sFileName; //Saved File's Name zgpPu4t
private int nSplitter; //Count of Splited Downloading File VKrKA71Z~
/ dn]`Ge)
R91u6r#
public SiteInfoBean() D3 E!jQ1
{//nSplitter的缺省值为5 n_] OYG>U
//default value of nSplitter is 5 |om3*]7
this("","","",5); ~Uz|sQ*G
} :TWHmxch
JeCEj=_Z
X_|} b[b
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }fxH>79g
{ -3b0;L&4>x
sSiteURL= sURL; lu.2ZQE
sFilePath = sPath; Ki@8
sFileName = sName; Ix5yQgnB}j
this.nSplitter = nSpiltter; 8%U)EU
t,P+~ A
WqU$cQD"
} 5O%}.}n
2Z..~1r
IPE(
public String getSSiteURL() ae1fCw3k
{ ck<4_?1]
return sSiteURL; PwNLJj+%
} q+G1#5
vqxTf)ys
n#]G!7
public void setSSiteURL(String value) -)<Nd:A
{ %BHq2~J
sSiteURL = value; h;unbz
} CGg6nCB
D{z=)'/F
gf@'d.W}
public String getSFilePath() ? 8!N{NV
{ ->#7_W
return sFilePath; @o^sp|k !
} Vgm{=$
B'0Il"g'
,>jm|BTD {
public void setSFilePath(String value) (}qLxZ/U
{ V[#lFl).
sFilePath = value; Ul@'z|
} FRF}V@~
"Ii!)n,
F;NZJEy
public String getSFileName() mg;AcAS.o,
{ ,zyrBO0 Eq
return sFileName; _bz,G"w+:
} Zd%\x[f9ck
n<$I,IRE
nMbV{h ,
public void setSFileName(String value) #5I "M WA
{ t[ MRyi)LF
sFileName = value; `4p9K
} BzUx@,
lJ,s}l7
|O+binq
public int getNSplitter() xO@OkCue
{ p.IfJ|
return nSplitter; e)bqE^JP
} M*{e e0\`r
|ZKchd8Yq
~gDtj&F
public void setNSplitter(int nCount) FxT [4
{ 6u7HO-aa
nSplitter = nCount; #sHP\|rA
} 5m3sjcp_
} t2$:*PvE
3G&1. 8
Ywr{/
/* C|JWom\J
**Utility.java >) ^!gz8
*/ 7I
package NetFox; 8vP)qy8
ljCgIfZ_4
w/<hyEpxg
public class Utility { n#fg7d%
0?sp
Aws TDM
public Utility() ^YZ#P0 y
{ MG@19R2s
Dx%fW`
;g*6NzdA
} (^4%Fk&I-
7> QtO
//线程睡眠 5-QXvw(TH
public static void sleep(int nSecond) ~!OjdE!u
{ U#P#YpD;==
try{ y%y#Pb|
Thread.sleep(nSecond); q.t5L=l^ r
} mB~&nDU
catch(Exception e) 6bn-NY:i
{ b +_E)4
e.printStackTrace (); }1P
} yC5|"+ A$
} 4c yv 8
*%e#)sn*
//日志 -d~'tti
public static void log(String sMsg) 5*r6#[S\
{ ~eP2PG
System.err.println(sMsg); ;D7jE+
} A!~o?ej
^pP 14y*go
@wPmx*SF
public static void log(int sMsg) zkOgL9 (_8
{ 73.b9mF
System.err.println(sMsg); m~K]|]iqQ
} zl[JnVF\6
} CAA~VEUL
2^aTW`>L
XTJ>y@
/* '9gI=/29D
**TestMethod.java 4Ojw&ys@V
*/ >>r:L3<!
package NetFox; df'g},_
L9@jmh*E
UK,P?_e
public class TestMethod { [1U_c*;i
DvCt^O*
/WfxI>v
public TestMethod() I'C,'
{ ///xx/weblogic60b2_win.exe :Eyv==
try{ 5,Y2Lzr
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); K;PpS*!
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); di5_5_$`o
SiteFileFetch fileFetch = new SiteFileFetch(bean); A@OV!DJe]
fileFetch.start(); 1c!},O
} ~}*;Ko\
catch(Exception e){e.printStackTrace ();} xTMTkVa+B
[)A#9L~s=
fLAF/#\2
} U:9vjY
M\f0 =`g
s|T7)PgR
public static void main(String[] args) F{,O+\
{ I\~V0<"jI
new TestMethod(); s|'L0` <B
} (/U1J
} @\?f77Of6
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