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)); in K]+H]{
} +BeA4d8b
for(int i=0;i<nEndPos.length-1;i++) DIABR%0
{ 0W0GSDx
nEndPos = nStartPos[i+1]; D6~KLSKm
} ;A4qE W
nEndPos[nEndPos.length-1] = nFileLength; |a#=o}R_
} "cyRzQ6EH
} iX o(
Atb`Q'Yrw
K@<*m!%<2
//启动子线程 b@c(Nv
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; AyWdJ<OU
for(int i=0;i<nStartPos.length;i++) ~s-bA#0S
{ #W6 6`{>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;*'I&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8 :WN@
nStartPos,nEndPos,i); h/oun2C
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Fv7]1EO.
fileSplitterFetch.start(); [n2zdiiBd
} Qo:vAv
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,,H;2xYf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); F!3p )?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~5&B#Sm[G
nEndPos = " + nFileLength); #K0/ >W
// fileSplitterFetch[nPos.length-1].start(); )w~1VcnJEp
tA^+RO4
T$`m!mQ4
//等待子线程结束 S{?l/*Il*_
//int count = 0; aGBd~y@e
//是否结束while循环 'z^'+}iyv
boolean breakWhile = false; xT+#K5
^^&H:q
LtH j
while(!bStop) -<g[P_#
{ e`co:HO`#
write_nPos(); e/cHH34
Utility.sleep(500); rrR"2WuGO
breakWhile = true; <o9AjASv\,
)u+O~Y95&i
k,$/l1D
for(int i=0;i<nStartPos.length;i++) 8!0fT}
{ 1$1>cuu
if(!fileSplitterFetch.bDownOver) &a4FGzR#
{ #q K.AZi
breakWhile = false; Cu5_OJ
break; cpl Ny?UIC
} Ux1j+}y
} -8l(eDm"m
if(breakWhile) q_6lD~~q^
break; sZ~03QvkT
|||m5(`S
VXiU5n^
//count++; )sW!s3>S>
//if(count>4) )Nqx=ms[(!
// siteStop(); |{(JUXo6K
} |$6Ten[B#
Zo-,TKgY'
@sG*u >
System.err.println("文件下载结束！"); U#[T!E
} +pq) 7
catch(Exception e){e.printStackTrace ();} yZ7)|j
} Vpp$yM&?
.rG~\Ws
w_o+;B|I
//获得文件长度 oexTz[
public long getFileSize() YhNrg?nS
{ P>u2""c
int nFileLength = -1; )5n0P Zi
try{ \9@}0}%`
URL url = new URL(siteInfoBean.getSSiteURL()); P5h*RV>oS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?mM:oQH+>
httpConnection.setRequestProperty("User-Agent","NetFox"); X31%T"
0C.5Qx
4CchE15
int responseCode=httpConnection.getResponseCode(); \pkK >R
if(responseCode>=400) jygUf|
{ EZ{{p+e^
processErrorCode(responseCode); [TQYu:e
return -2; //-2 represent access is error [L7s(Zs>
} tK[o"?2y
%,1TAmJfHa
PYC
String sHeader; P=1Ku|k
WY QVe_<z:
QnOs8%HS-
for(int i=1;;i++) 50|nQ:u,
{ (tq);m&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \a7m!v
//Utility.log(in.readLine()); IJKdVb~
sHeader=httpConnection.getHeaderFieldKey(i); c~/poFj
if(sHeader!=null) n$NM
{ S"@6,
if(sHeader.equals("Content-Length")) 5FuV=Yuc
{ A(uo%QE|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); U+#^>}wc
break; sVFX(yx0
} Xs|d#WbX
} *;McX
else 9{U@s
break; 0[fBP\H"Wr
} @`+\vmfD
} ^7ID |uMr
catch(IOException e){e.printStackTrace ();} ^!C
catch(Exception e){e.printStackTrace ();} x^c,cV+*
c%O97J.5b
}"nm3\Df
Utility.log(nFileLength); FeS ,TQ4j
S&-F(#CF^
H"A@Q.'
return nFileLength; l" ~ CAw;
} L4T\mP7D7*
|A,.mOT
'5*&
//保存下载信息（文件指针位置） `KLr!<i()
private void write_nPos() N-b'O`C
{ fj['M6+wd
try{ R\X;`ptT
output = new DataOutputStream(new FileOutputStream(tmpFile)); \2[tM/+Bs
output.writeInt(nStartPos.length); %-fS:~$
for(int i=0;i<nStartPos.length;i++) p %.Adxx
{ p<h(
// output.writeLong(nPos); bC"h7$3
output.writeLong(fileSplitterFetch.nStartPos); Ac{TqiIv
output.writeLong(fileSplitterFetch.nEndPos); 2Mq@5n
} _t;^\"\
output.close(); z>0$SBQ-
} cZ !$XXA`
catch(IOException e){e.printStackTrace ();} }@jJv||
catch(Exception e){e.printStackTrace ();} qhG2j;
} ">_|!B&wb^
^K::g)
O(-6Zqk8Q
//读取保存的下载信息（文件指针位置） ^8bc<c:P
private void read_nPos() >'=9sCi
{ %Qb}z@>fJk
try{ tUZfQ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); G9xO>Xp^Al
int nCount = input.readInt(); LttA8hf5q?
nStartPos = new long[nCount]; js;YSg{m
nEndPos = new long[nCount]; +A1*e+/b\
for(int i=0;i<nStartPos.length;i++) gBWr)R
{ =Ez@kTvOs
nStartPos = input.readLong(); |H,WFw1%}
nEndPos = input.readLong(); [>_zV.X
} 9bRUN<
input.close(); GutiqVP:B
} =aQlT*n%3
catch(IOException e){e.printStackTrace ();} DWx;cP8[
catch(Exception e){e.printStackTrace ();} gaNe\
} 8"NPj0
+t*I{X(
e2G;_:
private void processErrorCode(int nErrorCode) pRxVsOb
{ FIAmAZH}_
System.err.println("Error Code : " + nErrorCode); %jf|efxo
} pbqk
T*Ge67
4JXvP1`
//停止文件下载 -G?IXgG
public void siteStop() fWWB]h
{ GV) "[O
bStop = true; ts_|7Ev
for(int i=0;i<nStartPos.length;i++) xT* 3QwK
fileSplitterFetch.splitterStop(); Khv}q.)F
C|g1:#0
]oz>/\!
} qf ]le]J
} fuCt9Kjo<
//负责部分文件的抓取 E@)'Z6r1
**FileSplitterFetch.java 3}3b@:<
*/ ;gu4~LQw
package NetFox; |9.J?YP8 (
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Y%y
import java.io.*; O[L#|_BnEO
import java.net.*; HE_UHv
B]b/(Q+
z0a`*3 -2
public class FileSplitterFetch extends Thread { }M"])B I
"Dq^r9
=+?OsH v
String sURL; //File URL s S3RK
long nStartPos; //File Snippet Start Position W?!rqo2SP
long nEndPos; //File Snippet End Position K5^zu`19
int nThreadID; //Thread's ID LH @B\ mS
boolean bDownOver = false; //Downing is over 9M1DE
boolean bStop = false; //Stop identical ~Al3Dv9x
FileAccessI fileAccessI = null; //File Access interface .q:6F*,1M
ZdY$NpR,
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Hd7Vp:KM
{ _akjgwu
this.sURL = sURL; v+trHdSBYE
this.nStartPos = nStart; cUd>ahv
this.nEndPos = nEnd; 8'qlg|{!~
nThreadID = id; j"pyK@v2B
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (Uu5$q(
} omPxU2Jw
/CKnXU;
r}Gku0Hu_E
public void run() 0"TPY(n
{ 'Ox "YE
while(nStartPos < nEndPos && !bStop) #)48dW!n
{ *wd=&Z^19
L*|P'
@;y@Hf'Jv
try{ [ybK
URL url = new URL(sURL); o /1+ }f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =WZ9|e
httpConnection.setRequestProperty("User-Agent","NetFox"); j` * bz-
String sProperty = "bytes="+nStartPos+"-"; -k2|`t _
httpConnection.setRequestProperty("RANGE",sProperty); ?|}qT05
Utility.log(sProperty); d( ru5*p
;l0%yg/}
%BMlcm7Ec
InputStream input = httpConnection.getInputStream(); :f_oN3F p
//logResponseHead(httpConnection); 0yMHU[):~
%z-so?gF
7Lj:m.0O^
byte[] b = new byte[1024]; n;vZY
int nRead; Bf+~&I#E
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6CGk*s
{ ![vy{U.:`
nStartPos += fileAccessI.write(b,0,nRead); g3Hi5[-H
//if(nThreadID == 1) X_bB6A6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8WpNlB+:{
} \h0+` ;Q
M%Vp_ 0
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Utility.log("Thread " + nThreadID + " is over!"); %gSmOW2.c^
bDownOver = true; !Z{7X ^
//nPos = fileAccessI.write (b,0,nRead); Vu4LC&q
} \`2EfYJ{
catch(Exception e){e.printStackTrace ();} lZ2gCZ
} ]-a/)8
} [TqX"@4NS
u}_x
C8)s6
//打印回应的头信息 ni )G
public void logResponseHead(HttpURLConnection con) tux`-F
{ "A~D(1K
for(int i=1;;i++) 8ql<7RTM!
{ 4OO^%`=)M'
String header=con.getHeaderFieldKey(i); 1~2+w]-kU
if(header!=null) P%vouC0W
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ZnRj}y
Utility.log(header+" : "+con.getHeaderField(header)); KiE'O{Y
else >Lo'H}[pF
break; M)wNu
} Rp:I&f$Hk/
} (sH4T>
9U3}_
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public void splitterStop() CQ Ei(ty
{ a~JZc<ze
bStop = true; v/$<#2|
} U%#Vz-r
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maQxU(
} e8xNZG;
jJ2{g> P0P
xH,e$t#@@~
/* 0lOan
**FileAccess.java 4W E)2vkS
*//文件访问(定位，写) $ER$|9)KD
package NetFox; _Vt9ckaA
import java.io.*; e85E+S%
MAX?,-x
meThjCC
public class FileAccessI implements Serializable{ Z R~2Y?Wt9
Y=<zR9f`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #KHj.Vg
RandomAccessFile oSavedFile; B !rb*"[
long nPos; VtU2&
M-+!z5q~d
*qm>py`O
public FileAccessI() throws IOException =dQF}-{!
{ P9S)7&+DL
this("",0); '%TD#!a
} dPV<:uO
5*90t{#
mT|r:Yr:
public FileAccessI(String sName,long nPos) throws IOException qkC{IBN92
{ QMX
oSavedFile = new RandomAccessFile(sName,"rw"); 5s4x%L (~}
this.nPos = nPos; 6~?yn-Z
oSavedFile.seek(nPos); Gtvbm
} fmLDufx
}~0}B[Rf
Y$|KY/)H)
public synchronized int write(byte[] b,int nStart,int nLen) j~9Y0jz_
{ }y(cv}8Y
int n = -1; KxFA@3
try{ c2s73iz
oSavedFile.write(b,nStart,nLen); o(D_ /]'8
n = nLen; @|OGxQoC
} L$,Kdpj
catch(IOException e) cmd7-2
{ "s`#`'
e.printStackTrace (); *kj+6`:CPs
} ox";%|PP1
$0~1;@`rQ6
~0Zy$L/D
return n; N!\1O,
} EVLDP\w{
*rV{(%\m
R.GDCGAL
} N];K
p"*xyex
cb. -AlqQ
/* *W 04$N
**SiteInfoBean.java lm+s5}*%o
*/ )! kl:
package NetFox; Qdc)S>gp
6]HMhv
VPVg\K{
public class SiteInfoBean { 7kMO);pO
NKVLd_f k
X@A8~kj1
private String sSiteURL; //Site's URL j~9![s!
private String sFilePath; //Saved File's Path V9>$M=
private String sFileName; //Saved File's Name VjeF3pmBa
private int nSplitter; //Count of Splited Downloading File 3?!c<^"e
]&='E.f
e_S,N0
public SiteInfoBean() jF#Dc[*
{//nSplitter的缺省值为5 d@Wze[M?0
//default value of nSplitter is 5 }p8iq
this("","","",5); mK^E@uxN
} j:^gmZ;J
WK{F
f|j<Mj+\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?+{_x^
{ G6\`Iy68/v
sSiteURL= sURL; S]&aDg1y}
sFilePath = sPath; lXVh`+X/l
sFileName = sName; - Sn]`
this.nSplitter = nSpiltter; B_3N:K Y 9
UzV78^:,iD
'@^mesMG
} QUz4 Kt
cF"}}c1*M
<:StZ{o;
public String getSSiteURL() * COC&
{ wkJ@#jD*[
return sSiteURL; g/w<T+v
} iBKH\em/
od&wfwk(
dI%Nwl%
public void setSSiteURL(String value) _.m|Ml,`{
{ D'UIxc8
sSiteURL = value; |vBy=:
} :"K9(XKKU
fzN?X=
y (%y'xBP
public String getSFilePath() 4 *. O%
{ P_.AqEH
return sFilePath; <(45(6fQ
} vI"BNC*Q1
}YU\}T-P
owA.P-4
public void setSFilePath(String value) fM(~>(q&
{ "|E'E"_1
sFilePath = value; @F|pKf:M+
} -AB0uMot
>YcaFnY
{]4Zpev
public String getSFileName() OgzKX>N`A
{ gA]3h8%w
return sFileName; Xhpcu1nA
} JI&.d:
$h >rs
~bw=;xF{3
public void setSFileName(String value) i G%R'/*
{ :=:m4UJb
sFileName = value; AO(zl*4
} TALiH'w6|e
>h$Q%w{V
-6e^`c6{
public int getNSplitter() D]WrPWL8v
{ e0]%ko"
return nSplitter; 7gRR/&ZK
} P9jSLM
qv<^%7gq
rG%8ugap
public void setNSplitter(int nCount) ZT<VDcP{
{ ~sNBklK
nSplitter = nCount; (543`dqAmC
} tLP Er@
} _C,9c7K4
`r %lB
P!XO8X 1F
/* Ggbz
**Utility.java R}D[ z7
*/ nPjK=o`KR
package NetFox; @z`eqG,']
EZZE(dq@gf
qCF&o7*oN
public class Utility { x+[ATZ([
#[Rs&$vQm
&_\;p-1:
public Utility() RW<4",
{ &<- S-e
UUGX@
FgMQ=O2
} bicbCC6kC
'oUTY *
//线程睡眠 Fx:4d$>;
public static void sleep(int nSecond) <00=bZzX
{ SErh"~[
try{ 2dDhO
Thread.sleep(nSecond); WwxV}?Cf+
} @c).&7
catch(Exception e) yqP=6
{ x4v&%d=M
e.printStackTrace (); lWUQkS
} eWr6@
} p!\GJ a",
1yFIIj:^|
//日志 G7r.Jm^q
public static void log(String sMsg) g`)0 wP
{ l9&L$,=
System.err.println(sMsg); Z tc\4
} lcVG<*gf-
$v5 >6+-n
~JP3C5q
public static void log(int sMsg) *]!rT&E
{ .fS{j$
System.err.println(sMsg); 9ZuKED
} CV2#G*
} gJ>#HEkMB
u~~ ~@p
.9UrWBW\I
/* Qkc9X0J!
**TestMethod.java B[t>T>~
*/ 3#eAXIW[
package NetFox; -vc ,O77z"
+x<OyjY5?]
L^K,YlNBR
public class TestMethod { bgkBgugZhX
:m>Vp
_9?v?mL5;
public TestMethod() 5f2=`C0_
{ ///xx/weblogic60b2_win.exe \+:`nz3m
try{ OLoo#HW
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); cg9*+]rc
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =)a%,H
SiteFileFetch fileFetch = new SiteFileFetch(bean); q#\B}'I{
fileFetch.start(); OjrZ6
} i`?yi-R&
catch(Exception e){e.printStackTrace ();} \[%_ :9eq
RMdU1@
j]aIJbi
} G3h"Eo?>g
p(9[*0.};
XV,ce~ro[
public static void main(String[] args) IYa(B+nB)
{ e*d lGK3l
new TestMethod(); dJlK'zK
} U8@P/Z9
} p&D7&Sb[
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