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)); `84,R!
} h66mzV:`
for(int i=0;i<nEndPos.length-1;i++) \#C]|\
{ 1>umf~%Wa
nEndPos = nStartPos[i+1]; Q0g^%
} }yd!UU
nEndPos[nEndPos.length-1] = nFileLength; *-E'$
} :edy(vC<
} vu:] [2"0
g]d0B!Ar~
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//启动子线程 9vCCE[9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; K.b:ae^k
for(int i=0;i<nStartPos.length;i++) NC sem
{ Sf2xI'
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [* |+ it+!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), .d?LRf
nStartPos,nEndPos,i); TK0W=&6#A
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \Qf2:[-V0
fileSplitterFetch.start(); bYr*rEcA
} ZzxWKIE'c
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), h-DHIk3/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {vQ:4O!:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", s&XL{FE
nEndPos = " + nFileLength); `v)ZOw9&
// fileSplitterFetch[nPos.length-1].start(); `^|l+TJG
U/_hH*N"!
jsP+,brO
//等待子线程结束 5kojh _\
//int count = 0; i1*0'x
//是否结束while循环 yJ;Qe_up
boolean breakWhile = false; oN`khS]_v0
IR8yE`(h
RiFUa $
while(!bStop) }'K-1:
{ I1I-,~hO
write_nPos(); gEw9<Y
Utility.sleep(500); 9!.S9[[N
breakWhile = true; 6:6A"A
K=nDC.
YbnXAi\y|
for(int i=0;i<nStartPos.length;i++) 'W>y v
{ ';c 6
if(!fileSplitterFetch.bDownOver) $mE3 FJP>
{ '$EyVu!
breakWhile = false; E`<ou_0N@q
break; }6<5mq)%
} 4*Gv0#dga
} kS=nH9
if(breakWhile) Zq<j}vVJ
break; URg;e M#
VZ=:`)
`JpFqZ'58
//count++; nE*S3
//if(count>4) LExm#T`
// siteStop(); EP>Lh7E9n
} ;<B
Q"nw.FjUG
OFyy!r@?
System.err.println("文件下载结束！"); lS7L|
} cNxxX!P/
catch(Exception e){e.printStackTrace ();} U5H%wA['m
} njg0MZBqA
C$~ly=@
3en67l
//获得文件长度 d~%7A5
public long getFileSize() #)xlBq4cZ
{ `'<$N<!
int nFileLength = -1; >!s<JKhI
try{ r(uo-/7z
URL url = new URL(siteInfoBean.getSSiteURL()); EFh^C.S8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;hO6 p
httpConnection.setRequestProperty("User-Agent","NetFox"); + c3pe4
cl`Wl/Q#
d]O:VghY\
int responseCode=httpConnection.getResponseCode(); U\:Y*Ai
if(responseCode>=400) .x,y[/[[)
{ {TpbUj0
processErrorCode(responseCode); R@jMFh;
return -2; //-2 represent access is error SF+L-R<e
} nCWoco.xy
gFHBIN;u
hIV]ZYbH
String sHeader; \L~^c1s3r
>\<eR]12
Oj_]`
for(int i=1;;i++) bS~Y_]B
{ a<\n$E#q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); p:y\{k"
//Utility.log(in.readLine()); QR"+fzOL
sHeader=httpConnection.getHeaderFieldKey(i); l9Ol|Cb&
if(sHeader!=null) oJQS&3;/r
{ /"D,gn1S*
if(sHeader.equals("Content-Length")) H i8V=+
{ &-Ch>:[
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [>a3` 0M
break; PbZ%[F
} Bc }o3oc
} uCB9;+ Hjw
else qCcLd7`$
break; >YWK"~|i~
} )4B`U(%M~
} .tG3g:
catch(IOException e){e.printStackTrace ();} [q!]Ds" _
catch(Exception e){e.printStackTrace ();} -~8PI2
F*J1w|)F0
Yl&[_ l
Utility.log(nFileLength); q:)PfP+
RN)XIf$@_
MnFrQC
return nFileLength; QnS^ G{
} JW0\y+o~
bR"4:b>K
Z ;rM@x
//保存下载信息（文件指针位置） e< @$(w
private void write_nPos() 98u@X:3
{ ${z#{c1
try{ MMKN^a"GA
output = new DataOutputStream(new FileOutputStream(tmpFile)); kBA.N l7
output.writeInt(nStartPos.length); DjK7_'7(L
for(int i=0;i<nStartPos.length;i++) L3oL>r'|
{ >2>/ q?
// output.writeLong(nPos); h@O\j&#
output.writeLong(fileSplitterFetch.nStartPos); YC6guy>
output.writeLong(fileSplitterFetch.nEndPos); tM\BO0
} w?u3e+
output.close(); s'N<
} [!;sp~
catch(IOException e){e.printStackTrace ();} N}nE9z5
catch(Exception e){e.printStackTrace ();} BJ3<"D{.*4
} -?#iPvk6
36co'a4,
iTdamu`L
//读取保存的下载信息（文件指针位置） ]XlBV-@b
private void read_nPos() ,OwTi:yDr
{ >G!=lLyR
try{ 0OG 3#pE
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 71E~~$
int nCount = input.readInt(); a(yWIgD\\
nStartPos = new long[nCount]; ua=7YG
nEndPos = new long[nCount]; q0ab]g+
for(int i=0;i<nStartPos.length;i++) X6B,Mply
{ p3-~cr.LD
nStartPos = input.readLong(); 0 5?`W&:9
nEndPos = input.readLong(); eV(.\Lj
} $$p +~X
input.close(); p)Q5fh0-
} fO5L[U^`
catch(IOException e){e.printStackTrace ();} 5ad@}7&
catch(Exception e){e.printStackTrace ();} *uK!w(;2
} -0;{
%LHt{:9.
dj] O
private void processErrorCode(int nErrorCode) >\'}&oi
{ nXy"
System.err.println("Error Code : " + nErrorCode); rVOF
} 9_svtO]P
[-W~o.`
s H'FqV,)
//停止文件下载 IAb.Z+ig
public void siteStop() O['[_1n_u]
{ oMM@{Jp
bStop = true; JY:Fu
for(int i=0;i<nStartPos.length;i++) ZV5IZ&V!
fileSplitterFetch.splitterStop(); ESIeZhXVH
XH!n{Of
:*l\j"fX5
} X?r$o>db
} Bbb":c6w0
//负责部分文件的抓取 K`|V1L.m
**FileSplitterFetch.java _-v$fDrz
*/ H-m).^
package NetFox; 4w 7vgB
`'(@"-L:7
H\<PGC"_Y
import java.io.*; u!VrMH
import java.net.*; r24 s_
ay{]Vqi9
8y?q)y9h
public class FileSplitterFetch extends Thread { >k}Kf1I
tM:$H6m/(
dleLX%P
String sURL; //File URL 7{rRQ~s&g9
long nStartPos; //File Snippet Start Position %~Ymb&ugg
long nEndPos; //File Snippet End Position q*K.e5"'
int nThreadID; //Thread's ID B3&`/{u
boolean bDownOver = false; //Downing is over Ha20g/UN.
boolean bStop = false; //Stop identical ^eWD4Vp|4
FileAccessI fileAccessI = null; //File Access interface l=t$XWh!
\@:mq]Y
3R$*G8v
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException W&0KO-}ot
{ !5[5l!{x
this.sURL = sURL; 2z027P-Q
this.nStartPos = nStart; EEO)b_(
this.nEndPos = nEnd; U>kL|X3 V
nThreadID = id; *`wgqin
fileAccessI = new FileAccessI(sName,nStartPos);//定位 A;C)#Q/
} $#F7C[2N
7 a_99?J
\TXCq@
public void run() #R3|nL
{ 5Qgh\4
while(nStartPos < nEndPos && !bStop) =LMM]'no,
{ 97L#3L6t
ygfUy
R8<P}mv
try{ "94qBGf
URL url = new URL(sURL); "iTi+UZxe
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jr=erVHK
httpConnection.setRequestProperty("User-Agent","NetFox"); f8836<c
String sProperty = "bytes="+nStartPos+"-"; @t?uhT*Z=
httpConnection.setRequestProperty("RANGE",sProperty); O0,=@nw8.
Utility.log(sProperty); H)l7:a
I Z{DR
l^E)XWd
InputStream input = httpConnection.getInputStream(); GbN|!,X1m
//logResponseHead(httpConnection); YB'BAX<lI
xnD"LK
2uM\?*T@
byte[] b = new byte[1024]; L4-v'Z;
int nRead; :LEC[</yvl
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) As-xO~+
{ C;NG#4;'
nStartPos += fileAccessI.write(b,0,nRead); -7:_Dy
//if(nThreadID == 1) (S1Co&SX
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1=Nh<FuQ
} ct![eWsuB
~zT743
b;%>?U`>p
Utility.log("Thread " + nThreadID + " is over!"); :927y
bDownOver = true; tDIQ=
//nPos = fileAccessI.write (b,0,nRead); zyi;vu
} MGE8S$Z
catch(Exception e){e.printStackTrace ();} QNesiV0MI
} .-HwT3
} - HiRXB
8Xjp5
2\J-7o=P
//打印回应的头信息 $|%BaEyk
public void logResponseHead(HttpURLConnection con) r>ca17
{ -oR P ZtW
for(int i=1;;i++) R /0zB
{ ZF~@a+o
String header=con.getHeaderFieldKey(i); *'jI>^o
if(header!=null) 5VR=D\j
//responseHeaders.put(header,httpConnection.getHeaderField(header)); qz6@'1
Utility.log(header+" : "+con.getHeaderField(header)); K#!c<Li#
else .bvEE
break; dcbE<W#ss
} &Y3r'"
} OT{cP3;0*o
!ZrU@T
R7ze~[oF
public void splitterStop() J_rb3
{ I$HO[Z!
bStop = true; g?i0WS
} @K=C`N_22
GZWU=TC2{2
GW;O35 m
} #4BwYj(Sl
GLtd6;V
SA[wFc
/* iw\yVd^]:k
**FileAccess.java &.1qixXIr
*//文件访问(定位，写) vMYL( ]e
package NetFox; 5VZZk%oy
import java.io.*; 5DxNHEuS
13K|=6si
4U>g0
public class FileAccessI implements Serializable{ 51-@4E2:l:
kr>4%Ndm7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 92XG|CWX
RandomAccessFile oSavedFile; oFL7dL
long nPos; Gw-y6e'|Y
T7R,6qt
r%\%tz'`j
public FileAccessI() throws IOException %i5tf;x6i
{ '@dk3:3t
this("",0); >yf}9Zs
} ~`X$bF
g$h`.Fk,
N.UeuLz
public FileAccessI(String sName,long nPos) throws IOException ,xI FF-[0
{ W:8pmI
oSavedFile = new RandomAccessFile(sName,"rw"); Kw=][}d`D
this.nPos = nPos; )}lO%B'K
oSavedFile.seek(nPos); u5N&Wn{
} lsA?|4`mn
-BcnJK0
{R8)DK
public synchronized int write(byte[] b,int nStart,int nLen) sZPyEIXie
{ 9%Qlg4~<s
int n = -1; V `7(75
try{ OF/hD2V
oSavedFile.write(b,nStart,nLen); 2@,rIve
n = nLen; 3HqTVq`&
} pv8vW'G\E
catch(IOException e) 8_/,`}9
{ @Nn'G{8OG
e.printStackTrace (); L<k(stx~
} RA1K$D ?A
V 5D8z
c2Wp 8l
return n; MSE0z!t
} &}r-C97
qs{wrem
3b[.s9Q
} K_F"j!0
GIhX2EvAS
5Nl?Km~
/* <w3_EO
**SiteInfoBean.java !v. <H]s)
*/ gH yJ~
package NetFox; [ji')PCAi;
kMZo7 y
I%l2_hs0V
public class SiteInfoBean { x>tsI}C
@%jY
c 5 `74g
private String sSiteURL; //Site's URL U".5x~UC
private String sFilePath; //Saved File's Path upnX7as
private String sFileName; //Saved File's Name 9[R+m3V/`
private int nSplitter; //Count of Splited Downloading File +GncQs y
p z\8Bp}yo
Q^*4FH!W
public SiteInfoBean() Irui{%T
{//nSplitter的缺省值为5 1`GW>ZKv
//default value of nSplitter is 5 KW!+Ws
this("","","",5); >XxHp
} X?o6=)SC|
T:SqENV
E24j(>
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) re4A5Ev$
{ 8jY<S+[o
sSiteURL= sURL; aNBwb9X
sFilePath = sPath; |K" nSXzk
sFileName = sName; 0BH-kr
this.nSplitter = nSpiltter; ZW4$Ks2]Y
Hb/8X !=
D#A6s32a
} 1Tr%lO5?6
U>sEFzBup
gJ~CD1`O
public String getSSiteURL() -@ra~li,yQ
{ h_]*|[g
return sSiteURL; Ckc5;:b&m
} yb,X }"Et
vR&b2G7o
[=",R&uD$
public void setSSiteURL(String value) `Tei
{ C80< L5\
sSiteURL = value; b +Z/nfS
} Ahc9HA2
;2$0j1>
5WvsS( 9H
public String getSFilePath() )7p(htCz5
{ ^#IE t#
return sFilePath; Wt=\hixj-
} Z1Qv>@u
K>C@oE[W
0Y:)$h2?
public void setSFilePath(String value) $ w+.-Tr
{ =sAU5Ag68
sFilePath = value; Z*ag{N
} r`\@Fv,&#
v^)B[e!
mZM,"Wq,
public String getSFileName() CI-1>= "OE
{ ahQY-%>
return sFileName; 4j8$&~/
} rNurzag
#d06wYz=
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public void setSFileName(String value) v*&jA8D
{ u:Ye`]~o
sFileName = value; m'N8[ o|h
} evpy%/D
jgS3#
ANJL8t-m
public int getNSplitter() tfu`_6
{ ! ,{zDMA
return nSplitter; P]TT8Jgw
} {9X mFa
vCNq2l^CW
#6v357-5
public void setNSplitter(int nCount) ^d@2Y0hH
{ bt(Y@3;
nSplitter = nCount; )EQz9
} v~yw-}fk%
} H^54o$5
KVh#"]<WV
1)jeawVmj
/* `SOQPAnK+;
**Utility.java RRpY%-8M
*/ \yZVn6GVr
package NetFox; i7Cuc+j8
_C(fz CK
{}rnn$HQe
public class Utility { 5Zd oem
FJ4,|x3v[x
a+\<2NXYD
public Utility() D9NQ3[R 9
{ 5gII|8>rQ
jvAjnh#
\*'@F+
} Kn<+Au_]L
Z4c'1-lh
//线程睡眠 /qMnIo
public static void sleep(int nSecond) y:^o._
{ /]_|uN)Q
try{ j"hEs(t
Thread.sleep(nSecond); &3;"$P
} D~BL Txq
catch(Exception e) g4W/T
{ H(tC4'tA
e.printStackTrace (); D[?;+g/
} !icI Rqcf=
} .@%L8_sMR
v|\#wrCT?
//日志 |cP:1CRzi
public static void log(String sMsg) \HkBp&bqK
{ l qwy5#
System.err.println(sMsg); l2:-).7xt
} 3;VH'hh_
%p$XK(6
vd(S&&]o1
public static void log(int sMsg) _p5#`-%mM
{ >j3':>\U
System.err.println(sMsg); 7}y@VO6]
} 6wj o:I
} u$C\#y7
F[SZwMf29
Maq`Or|4
/* L+p}%!g
**TestMethod.java Q{?\qCrrYl
*/ dNNXMQ0"
package NetFox; m;\nMdn
jf`w8*R
=}kISh
public class TestMethod { mXyN{`q=
U;4i&=.!
[DDe}D3C
public TestMethod() /RMtCa~
{ ///xx/weblogic60b2_win.exe @'):rFr@F
try{ U~)5{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); az:}RE3o
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); pe0ax-Zv
SiteFileFetch fileFetch = new SiteFileFetch(bean); }/&Zo=Q$
fileFetch.start(); :$k1I-^R
} =0]K(p,
catch(Exception e){e.printStackTrace ();} m$^5{qpg
.?5 ~zK
fS/:OnH
} M>Tg$^lm
}2LWDQ;po
%&&)[
public static void main(String[] args) /g!ZU2&l
{ K>e-IxA);0
new TestMethod(); >6jal?4u-
} V^R,j1*
} " "m-5PGYo
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