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)); ,vDSY N6
} /Fj*sS8
for(int i=0;i<nEndPos.length-1;i++) 8*x/NaH /\
{ \Gl>$5np
nEndPos = nStartPos[i+1]; `8 Ann~Z|k
} PAD&sTjE*
nEndPos[nEndPos.length-1] = nFileLength; jjT)3 c:J[
} qs$w9I
} 5M v<8P~
QZwZ4$jkiO
tkIpeL[d
//启动子线程 1[] 9EJ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; GI5#{-)
for(int i=0;i<nStartPos.length;i++) R$m?aIN
{ |S6L[Uo
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Au10]b
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <D`VFSEJ
nStartPos,nEndPos,i); a&z$4!wQB
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .;J6)h
fileSplitterFetch.start(); vu@@!cT6e
} [,yYr
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )BeBxo7lv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); )+ (GE
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", gmUX 2x(
nEndPos = " + nFileLength); vqhu%ZyP
// fileSplitterFetch[nPos.length-1].start(); _uL8TC^
^ *1hz<
0/5{v6_rG
//等待子线程结束 (jI_Dk;
//int count = 0; {Gvv^.H7
//是否结束while循环 IkP; i_|
boolean breakWhile = false; GMKY1{
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while(!bStop) nPR*mbW
{ cI\&&<>SlG
write_nPos(); Oil~QAd,
Utility.sleep(500); oiRrpS\T.
breakWhile = true; ^Lc, w
fB=j51Lw
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for(int i=0;i<nStartPos.length;i++) v"YaMbu
{ YH,u*.I^/
if(!fileSplitterFetch.bDownOver) !g[UFw
{ LjySO2
breakWhile = false; kInU,/R*
break; kXN8hU}iq
} R ~?9+
} G`r/ tesW
if(breakWhile) 9GgXX9K
break; QB5,Vfoux
@bIZ0tr4
bLSUF`-z
//count++; {k uC+~R
//if(count>4) 3~EPX`#[W
// siteStop(); }X9G(`N(}
} @/8O@^
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8 3Tv-X
System.err.println("文件下载结束！"); r7+Ytr
} VmON}bb[zz
catch(Exception e){e.printStackTrace ();} MlV3qM@
} B=)tq.Q7
ih=O#f|
)mu[ye"p
//获得文件长度 BIxjY!!"
public long getFileSize() m\f}?t
{ Ksff]##H
int nFileLength = -1; rqTsKrLe
try{ IFbN ]N0
URL url = new URL(siteInfoBean.getSSiteURL()); x31Jl{x8\?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .23Yqr'zT
httpConnection.setRequestProperty("User-Agent","NetFox"); ?wVq5^ e
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FO:k >F
int responseCode=httpConnection.getResponseCode(); | Zj=E$
if(responseCode>=400) s x2\
{ +[":W?j
processErrorCode(responseCode); ~COd(,ul
return -2; //-2 represent access is error >Yx,%a@~R
} !bBx'
mvu$
y4%[^g~-
String sHeader; %\B@!4]
M7.H;.?
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for(int i=1;;i++) \hDjZ
{ /Jc54d
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )@_5}8
//Utility.log(in.readLine()); vw*,_f
sHeader=httpConnection.getHeaderFieldKey(i); -r%k)4_
if(sHeader!=null) ^=arKp,?5
{ Vrt*,R&
if(sHeader.equals("Content-Length")) aa&\HDh*
{ ;4<!vVf e
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <"Yx}5n.
break; Q\pI\]p:
} Z$y~:bz
} $O9,Gvnxx
else % U|4%P
break; C zxF
} "H|hN
} lNx:_g:SrZ
catch(IOException e){e.printStackTrace ();} Su]p6B
catch(Exception e){e.printStackTrace ();} |W*i'E
Vi>`g{\
<KrfM
Utility.log(nFileLength); b,lIndj#
8F/JOtkGMt
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return nFileLength; ;uaZp.<um&
} MXs]3M
I`q"
6]fz;\DgP
//保存下载信息（文件指针位置） .&rL>A2U
private void write_nPos() N4u-tlA
{ h 6juX'V
try{ ~y>NJM>1
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^v&)z,
output.writeInt(nStartPos.length); B qcFbY
for(int i=0;i<nStartPos.length;i++) Ja{[T
{ fBnlB_}e
// output.writeLong(nPos); u5A$VRMN
output.writeLong(fileSplitterFetch.nStartPos); S3sxK:
output.writeLong(fileSplitterFetch.nEndPos); vJsx_i\i
} aH*5(E]
output.close(); 1? Im"
} -op(26:W<
catch(IOException e){e.printStackTrace ();} UgD&tD0fp
catch(Exception e){e.printStackTrace ();} I2)#."=Ew
} fcisDu8n
)<vuv9=k\%
6$ ag<
//读取保存的下载信息（文件指针位置） ;` !j~
private void read_nPos() ?y2v?h"
{ L)3JTNiB
try{ ^ ^k]2oG
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %ql2 XAY
int nCount = input.readInt(); ,2]a<0m
nStartPos = new long[nCount]; Qn`Fq,uvL
nEndPos = new long[nCount]; v|wO qS
for(int i=0;i<nStartPos.length;i++) .NT9dX
{ -$o4WSd~
nStartPos = input.readLong(); 5?-@}PL!Y
nEndPos = input.readLong(); {xCqz0
} G'(8/os{
input.close(); n0opb [?
} 0l2@3}e
catch(IOException e){e.printStackTrace ();} fu{.Ir
catch(Exception e){e.printStackTrace ();} ~c${?uf
} "w:?WS
!c;BOCqa
M1J77LfS8
private void processErrorCode(int nErrorCode) a$]i8AeG
{ .y>G/8_i
System.err.println("Error Code : " + nErrorCode); o$k9$H>Na
} u9D#5NvGs
>_SqM!^v
TgvBy
//停止文件下载 siD/`T&
public void siteStop() oE&#Tl?Vt
{ ObSRd$M
bStop = true; aLO'.5 ~^
for(int i=0;i<nStartPos.length;i++) Gk]6WLi
fileSplitterFetch.splitterStop(); ?(>fB2^
eY8rm
d< b,].
} [6f(3|"
} .a7!*I#g
//负责部分文件的抓取 j S<."a/n
**FileSplitterFetch.java WbGN 5?9Q
*/ @q+X:K5b
package NetFox; 1[40\sM
PEPf=sm
v-!^a_3Ui
import java.io.*; Og<nnq
import java.net.*; A_2oQ*
L<Q>:U.@\
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public class FileSplitterFetch extends Thread { TcOmBKps'
@y(<4kLz
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String sURL; //File URL Ms14]M[\
long nStartPos; //File Snippet Start Position 4Bk9d\z
long nEndPos; //File Snippet End Position C(}N*e1
int nThreadID; //Thread's ID w=QW8q?
boolean bDownOver = false; //Downing is over KYR64[1
boolean bStop = false; //Stop identical :Hq#co
FileAccessI fileAccessI = null; //File Access interface `w EAU7m:
9;R'Xo=y
L'r gCOJ<
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException UB,:won
{ a}[ 1*_G
this.sURL = sURL; @k3xk1*
this.nStartPos = nStart; ]h?p3T$h
this.nEndPos = nEnd; N^%7
nThreadID = id; o+F< r#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5LzP0F U
} aM|;3j1p
.^V9XN{'a
l#fwNM/F
public void run() tFu"h1
{ Qz`v0"'w
while(nStartPos < nEndPos && !bStop) 6D/K=-
{ Q|(G -
m#`1.5%
d'k99(vy
try{ v`Yj)
URL url = new URL(sURL); 5DmW5w'p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LGq T$ O|
httpConnection.setRequestProperty("User-Agent","NetFox"); !z2KQ 4C
String sProperty = "bytes="+nStartPos+"-"; &9F(C R
httpConnection.setRequestProperty("RANGE",sProperty); 1fqJtP6
Utility.log(sProperty); T_Cj=>L
>b2wFo/em
U o[\1)
InputStream input = httpConnection.getInputStream(); ZK5 wZU
//logResponseHead(httpConnection); #D-Ttla
HUalD3 \
'g:.&4x_w
byte[] b = new byte[1024]; 0bl8J5Ar5
int nRead; D.*o^{w|
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) k nljc^
{ 74fE%;F
nStartPos += fileAccessI.write(b,0,nRead); QE+HL8c^s
//if(nThreadID == 1) L~{3W
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W]I+Rlv)U
} Wgb L9'}B
@G^m+-
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Utility.log("Thread " + nThreadID + " is over!"); +d=w%r)
bDownOver = true; [Zne19/
//nPos = fileAccessI.write (b,0,nRead); =XFyEt
} z -uW,
catch(Exception e){e.printStackTrace ();} %<{1N|
} MJ<jF(_=
} 6h?)x
+;bP.[Z
B3&C=*y
//打印回应的头信息 {ep.So6
public void logResponseHead(HttpURLConnection con) X.eocy
{ ?,w9e|
for(int i=1;;i++) }~Ir&
{ 97vQM
String header=con.getHeaderFieldKey(i); S!h=HE
if(header!=null) Ogu";p(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %r]V:d+
Utility.log(header+" : "+con.getHeaderField(header)); J*4T|#0
else A,4Z{f83
break; -+y3~^EYm,
} 22@w:
} n;e.N:p
sFw;P`
g17 fge6%
public void splitterStop() O96%U$W
{ "f:_(np,
bStop = true; Ou{VDE
} zg$NrI&
/"@cv{
=F09@C,
} }#2I/dn
7V-uQ)*
i2E@5 v=|Y
/* v(;n|=O
**FileAccess.java `]F#j ]"
*//文件访问(定位，写) Y2}m/7aF
package NetFox; 7)*q@
import java.io.*; #|K5ma
|O{kv}YZ
`JcWH_[
public class FileAccessI implements Serializable{ xM?tdQ~VHY
6 -BC/
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^#]eCXv
RandomAccessFile oSavedFile; cUr5x8<W).
long nPos; 7{p6&xXx
HL%|DCo
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public FileAccessI() throws IOException t'[`"pp=
{ S]?I7_
this("",0); c~u91h?
} BBa!le9P
{R?VB!dR
")9jt^
public FileAccessI(String sName,long nPos) throws IOException H3+P;2{
{ 465?,EpS
oSavedFile = new RandomAccessFile(sName,"rw"); vF9fXY=
this.nPos = nPos; V^< Zs//7
oSavedFile.seek(nPos); pYh\l.@qf
} DDe`Lb%%
_8e0vi!~2
GYtp%<<9;
public synchronized int write(byte[] b,int nStart,int nLen) ]QJ7q}
{ wQYW5X
int n = -1; f1|&umJ$
try{ =g$%jM>35
oSavedFile.write(b,nStart,nLen); cToT_Mk
n = nLen; ^bECX<,H
} '#>(JN5\
catch(IOException e) uQg&]bSv
{ "Ug+#;}p$
e.printStackTrace (); 7MIrrhk
} +iw4>0pi
o\X|\nUk
MH=Ld=i
return n; p. KT=dZT
} g/gaPc*86
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nnCz!:9p
} '^(qlCI
D{6<,#P{w
M=4`^.Ocm
/* T!-ly7-`
**SiteInfoBean.java w[#*f?at~
*/ aa}U87]k
package NetFox; M:oZk&cs
f=-R<l
VYkUUp
public class SiteInfoBean { @_ Tq>tOr&
=l>=]O~h
VyWzb
private String sSiteURL; //Site's URL n$<n Yr`X
private String sFilePath; //Saved File's Path ,,;vG6^a
private String sFileName; //Saved File's Name NG?g(
private int nSplitter; //Count of Splited Downloading File T>w;M?`9K
8Yf=)
cC9haxW
public SiteInfoBean() DK1{Z;Z
{//nSplitter的缺省值为5 %rO)w?
//default value of nSplitter is 5 0~e6\7={
this("","","",5); Ehq [4}
} |OIU)53A-
p5J!j I=
95Q^7oI
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,3Nna:~f
{ ?;ZnD(4?
sSiteURL= sURL; $`<-;kI
sFilePath = sPath; !*o{xq
sFileName = sName; {}P~nP
this.nSplitter = nSpiltter; w`[`:H_z
5Q,j+
9>;CvR
} &t}6sD9o
&}d5'IRT
f<>CSjQ4c
public String getSSiteURL() fzUG1|$e
{ Nb)Mh
return sSiteURL; ( ;_AP.
} ie7P^:T|+
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public void setSSiteURL(String value) S2EV[K8#
{ o0TB>DX$`
sSiteURL = value; 0@RVM|
} =b>e4I@
Fi# 9L
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public String getSFilePath() 68~5Dx
{ Zi<(>@z2
return sFilePath; DuIgFp
} py6O\` \
`t+;[G>ZE
FBa-gm<9
public void setSFilePath(String value) 4GS:kfti
{ I>lblI$7
sFilePath = value; 37*2/N2
} X39%O'
,_@) IN
Uurpho_~
public String getSFileName() h{^MdYJ
{ "g5MltH
return sFileName; NT{'BJ
} izLB4pk$
[XkWPx`
B?ipo,2~{
public void setSFileName(String value) Nzb=h/;
{ k0D):
sFileName = value; =)J)xH!N
} rdH^"(
?(M]'ia{
G> sqfYkK
public int getNSplitter() mteQRgC
{ {"O-/* f+(
return nSplitter; r(<91~Ww
} 3gv?rJV
r9p ((ir
I_|W'%N]
public void setNSplitter(int nCount) Nhtc^DX
{ fC/P W`4Ae
nSplitter = nCount; B^.:dn
} d"S\j@
} _p<wATv?7t
%&wi@ *#
:0p$r pJP
/* HC"yC;_
**Utility.java y2nT)nL
*/ ]'Gz~Z%>F
package NetFox; K{XE|g
sTvw@o*
>AWWwq -
public class Utility { @*WrHoa2N
=FQH5iSd
L }R-|
public Utility() 10tTV3`IM
{ a[=ub256S
Wr8}=\/
KK4rVb:-
} [Bj\h7G
w8F`RRHEE
//线程睡眠 'fZ\uMdTx
public static void sleep(int nSecond) hJ?PV@xy
{ XE#$|Z
try{ ycf)*0k
Thread.sleep(nSecond); 2B+qS'OT
} T%E/k# )q
catch(Exception e) 9ZDbZc
{ [}5mi?v
e.printStackTrace (); E`|vu*l7
} g|j15&x
} /&l4 sF1
34L1Gxf
//日志 .]N`]3$=
public static void log(String sMsg) "O_)~u
{ 0iKAg
System.err.println(sMsg); !:v7SRUXb
} $Qxy@vU
HTSk40V
m@YK8c#$
public static void log(int sMsg) !PgwFJ
{ ?>My&yB
System.err.println(sMsg); +mYK
} T-x}o
} Kp19dp}'b
#P {|7}jk
;,xM*
/* s\Ln
**TestMethod.java /Eu|Jg=I
*/ >uFFTik
package NetFox; whFJ]
4ZkaH(a1
Xm<|m#
public class TestMethod { +]Ev
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B/Ltb^a
public TestMethod() s0DT1s&
{ ///xx/weblogic60b2_win.exe 'f8'|o)
try{ ;_0frX
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [MF&x9Ss?%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *hh9 K
SiteFileFetch fileFetch = new SiteFileFetch(bean); 83VFBY2q
fileFetch.start(); #VsS C1
} BE!l{
catch(Exception e){e.printStackTrace ();} 2I7|hZ,
)!;20Po
-op)X>
} !t?5U_on
Lz!H@)-mr
Zh_3ydMD1
public static void main(String[] args) ((M>To_l
{ <`NtTG
new TestMethod(); [kMWsiZ
} P1|3%#c
} lHE \Z`
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