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)); =skw@c^
} ur,!-t(~t
for(int i=0;i<nEndPos.length-1;i++) {WE1^&Vk-}
{ s^{hdCCl67
nEndPos = nStartPos[i+1]; 9BJP|L%q
} PE~umY]
nEndPos[nEndPos.length-1] = nFileLength; _qq> 43
} CHeU?NtFps
} 0GtL6M@pP
^}+qd1r
iz&$q]P8
//启动子线程 avmuI^LLs
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; S4m??B
for(int i=0;i<nStartPos.length;i++) ,F,\bp}
{ ' DZYN {}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6 K+DgNK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =r3%jWH6
nStartPos,nEndPos,i); O]\6Pv@N
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); GESEj%R/b
fileSplitterFetch.start(); F~`Yh6v
} p5C:MA~*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), TzC'xWO
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :ub 4p4h*
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", OD*\<Sc
nEndPos = " + nFileLength); csceu+IA
// fileSplitterFetch[nPos.length-1].start(); ;#F/2UgHB
Q M#1XbT
L9|55z
//等待子线程结束 ^usZ&9"@P
//int count = 0; J4yL"iMt
//是否结束while循环 ZPktZ
boolean breakWhile = false; 6`>WO_<z
</UUvMf"
;"}yVV/4
while(!bStop) yJCqP=
{ F3-<F_4.w
write_nPos(); \(ygdZ{R
Utility.sleep(500); S_E-H.d"
breakWhile = true; 0Jz5i4B
*Kpk1
KW* 2'C&
for(int i=0;i<nStartPos.length;i++) {`FkiB` i
{ SXYH#p
if(!fileSplitterFetch.bDownOver) {t.5cX"[
{ k`l={f8C
breakWhile = false; emhI1 *}
break; xJphG
} k$u\\`i]oC
} {:D8@jb[
if(breakWhile) `&\jOve
break; 1ZL91'U
0rt@4"~~w
UlG8c~p
//count++; =cwQG&as
//if(count>4) qO;.{f
// siteStop(); aC\O'KcH
} y /$Q5P+o
f<14-R=
g*]hmkYe9
System.err.println("文件下载结束！"); B3+9G,or
} [y(DtOR
catch(Exception e){e.printStackTrace ();} Q]JWWKt6rV
} aG"j9A~ &
(i1JDe
1JRM@!x
//获得文件长度 1V\tKDM
public long getFileSize() )\S3Q
{ U$*AV<{%
int nFileLength = -1; Jy#c 6
try{ dRdI('
URL url = new URL(siteInfoBean.getSSiteURL()); wzXIEWJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?QDHEC62
httpConnection.setRequestProperty("User-Agent","NetFox"); y*F !k{P
F@8G,$
N('=qp9
int responseCode=httpConnection.getResponseCode(); JPH! .@
if(responseCode>=400) <r9L-4
{ 9J3@8h p
processErrorCode(responseCode); 4YuJ-
return -2; //-2 represent access is error %^bHQB%
} 'YKzs;y$
)x!b{5'"7
;u+k!wn
String sHeader; 86*9GS?U(
.wU0F
.tdaj6x
for(int i=1;;i++) |rU?
{ CPW^pGT+i
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $U_M|Xa
//Utility.log(in.readLine()); y%Q0* _
sHeader=httpConnection.getHeaderFieldKey(i); AiP#wK;
if(sHeader!=null) ]u]BxMs
{ t5| }0ID-
if(sHeader.equals("Content-Length")) S/itK3
{ - w{`/
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Bj=lUn`T:
break; = 9Ow!(!@
} i,H(6NL.
} i/C`]1R/
else V< Ib#rd'
break; *:5S*E&}V
} GM~Ek]9C%
} z#[PTqD-_
catch(IOException e){e.printStackTrace ();} |rgp(;iO
catch(Exception e){e.printStackTrace ();} 3s]aXz:
=bBV A0y
"t.Jv%0=
Utility.log(nFileLength); !K8Kw W|X
9{GEq@`7
%(uYYr 6
return nFileLength; r|_@S[hZg
} ]\C wa9
e9=UTn{!
6e;POW
//保存下载信息（文件指针位置） `f[
private void write_nPos() 0!Vza?9
{ `j1b5&N;7
try{ UkTq0-N;2
output = new DataOutputStream(new FileOutputStream(tmpFile)); YYN'LF#j
output.writeInt(nStartPos.length); ,M.phRJ-`
for(int i=0;i<nStartPos.length;i++) 4,P(w+
{ )ZW[$:wA
// output.writeLong(nPos); /fSsh;F
output.writeLong(fileSplitterFetch.nStartPos); [;Y,nSw
output.writeLong(fileSplitterFetch.nEndPos); `0_,>Z
} h6Q~Di
output.close(); AI^!?nJ%'
} -O^R~Q_`w
catch(IOException e){e.printStackTrace ();} 'ti~TG
catch(Exception e){e.printStackTrace ();} q^DQ9B
} ]#\De73K
'5m4kDs
FNw0x6,~R
//读取保存的下载信息（文件指针位置） dC<2%y
private void read_nPos() #z1/VZ
{ 5SMV3~*P
try{ k\TP3*fD
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); yW)r`xpY
int nCount = input.readInt(); [[#R ry
nStartPos = new long[nCount]; B1V+CP3t
nEndPos = new long[nCount]; Eq?U$eE
for(int i=0;i<nStartPos.length;i++) I/*^s
{ SHYbQF2
nStartPos = input.readLong(); ~>#?.f
nEndPos = input.readLong(); {pc (b
} a&Z,~Vp
input.close(); ]6 HR
} p9E/#U8A_
catch(IOException e){e.printStackTrace ();} wVq9t|V
catch(Exception e){e.printStackTrace ();} {4$aA*
} DDq?4
%a?\y_a=b
n)j0h-
private void processErrorCode(int nErrorCode) _o T+x%i
{ ? *v*fs0
System.err.println("Error Code : " + nErrorCode); `6P2+wf1j~
} Yr*!T= z
S"t\LB*'Ls
~dC.,"
//停止文件下载 iR!]&Oh
public void siteStop() c{IL"B6>
{ Ou4 `#7FR
bStop = true; (;;.[4,y
for(int i=0;i<nStartPos.length;i++) zsLMROo3
fileSplitterFetch.splitterStop(); 9X&=?+f
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Q;s{M{u
} R,s}<N$
} r1Hh @sxn
//负责部分文件的抓取 lWn}afI
**FileSplitterFetch.java +c8t~2tuN
*/ P}^Y"zF2
package NetFox; (5;nA'
sPMICIv|
2^=8~I!n&
import java.io.*; ucJ}KMz
import java.net.*; Ifokg~X~G
njZJp|y6
{<$tEj:
public class FileSplitterFetch extends Thread { FUXJy{n6"2
01&@8z'E
MGf*+!y,
String sURL; //File URL +w7U7" xQ
long nStartPos; //File Snippet Start Position |2=@8_am
long nEndPos; //File Snippet End Position #].qjOj
int nThreadID; //Thread's ID tLU@&NY`
boolean bDownOver = false; //Downing is over @^<&LG5^
boolean bStop = false; //Stop identical U)M&AYb
FileAccessI fileAccessI = null; //File Access interface *fs[]q'Q
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BNF*1JO
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException | TG6-e_
{ ,zuS)?
this.sURL = sURL; 7n o6
this.nStartPos = nStart; xkRS?Q g
this.nEndPos = nEnd; +p`BoF9~
nThreadID = id; q{_f"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 C4qK52'2s
} &Nh zEl1
k~Q 5Cs
'7}2}KD
public void run() `zrg?
{ aOw#]pB|
while(nStartPos < nEndPos && !bStop) Cn{v\Q~.4
{ lo1bj*Y2
\#]C !JQ
op/_:#&'
try{ ^eyVEN
URL url = new URL(sURL); OSfT\8YA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $f _C~O
httpConnection.setRequestProperty("User-Agent","NetFox"); 9XYm8g'X
String sProperty = "bytes="+nStartPos+"-"; ce#Iu#qT
httpConnection.setRequestProperty("RANGE",sProperty); Zoc4@% n
Utility.log(sProperty); 4x&Dz0[[S
5Po:$(
+$#<gp"
InputStream input = httpConnection.getInputStream(); nW^h +
//logResponseHead(httpConnection); "O-X*>?f
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.p.( \5Fo
byte[] b = new byte[1024]; )hl7)~S<
int nRead; 10h;N[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) z5oJQPPi
{ \NMqlxp2
nStartPos += fileAccessI.write(b,0,nRead); 0%< hj
//if(nThreadID == 1) G3`9'-2q@c
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .%)uCLZr$
} x/CM)!U)
hJ]Oa7r
|/H?\]7
Utility.log("Thread " + nThreadID + " is over!"); =4'V}p
bDownOver = true; 3!\h'5{
//nPos = fileAccessI.write (b,0,nRead); |OAM;@jH
} qjhk#\y
catch(Exception e){e.printStackTrace ();} -.y1]4
} [|YvVA
} SD:D8"8
b9#(I~}
kW2DKr-[
//打印回应的头信息 RD"-(T
public void logResponseHead(HttpURLConnection con) i}zz!dJTE
{ Tg"? TZO~
for(int i=1;;i++) @MVul_@6
{ N&p0Emg
String header=con.getHeaderFieldKey(i); (&Jo. <
if(header!=null) Hi=</ Wy;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); j5Da53c#^
Utility.log(header+" : "+con.getHeaderField(header)); 4_iA<}>|
else 1<1+nGO
break; GS=E6
} x>B\2;
} ^\Z+Xq1~/
4ryG_p52l
MJqWc6{ n
public void splitterStop() 2C}Yvfm4
{ n[gE[kw
bStop = true; d{Jk:@.1
} gSw4\R
Ex zB{"
"^6Fh"]
} jd-ccnR l
.MG83Si
KUYwc@si\
/* =f y|Dm74
**FileAccess.java &PRoT#,
*//文件访问(定位，写) J,)ytw]
package NetFox; h2T\%V_j
import java.io.*; aQ$sn<-l
2aCf?l(
te2vv]W1
public class FileAccessI implements Serializable{ KcpYHWCa.
\u{4=-C.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 u>.a;BO
RandomAccessFile oSavedFile; G 3,v'D5
long nPos; bY.VNA
!CX WoM
*!$Z5Im
public FileAccessI() throws IOException a-E}3a
{ -$o0P'Vx
this("",0); 7`;f<QNo
} iLZY6?_^
Ms,MXJtH
dt:$:,"
public FileAccessI(String sName,long nPos) throws IOException KS93v9|
{ {Ba&
oSavedFile = new RandomAccessFile(sName,"rw"); y)&K9 I
this.nPos = nPos; X.;VZwT+
oSavedFile.seek(nPos); C 5gdvJN
} c/tB_]
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O#ZZ PJ"
public synchronized int write(byte[] b,int nStart,int nLen) PBb&.<
{ 9/29>K_
int n = -1; PjEJC@n
try{ 1J"9Y81
oSavedFile.write(b,nStart,nLen); g assOd
n = nLen; 5[SwF&zZ
} SDil\x
catch(IOException e) ebI2gEu;a
{ >*h+N? m
e.printStackTrace (); `8W HVC$
} O1\Hx8^
9D1WUUa
E3O^Tg?j
return n; }|=/v(D
} ]5S`y{j1
4\&Y;upy+
F!EiF&[\J
} QcQ%A%VIV
|A'I!Jm
kJ FWk
/* \(P?=] -
**SiteInfoBean.java E|f[#+:+
*/ Ha-]U:Vcx
package NetFox; U[f00m5{HV
{:uv}4Z
BNNM$.ZIQ
public class SiteInfoBean { rnj$u-8
u3+B/ 5x
tj@(0}pi4
private String sSiteURL; //Site's URL 1B2#uhT]r
private String sFilePath; //Saved File's Path v>} +->f
private String sFileName; //Saved File's Name rl%,9JD!
private int nSplitter; //Count of Splited Downloading File PmE)FthdP(
G$i)ELs
950N\Y@u
public SiteInfoBean() %|(c?`2|
{//nSplitter的缺省值为5 < v]
//default value of nSplitter is 5 p 4>ThpX
this("","","",5); 70c]|5
} lJu^Bcrv
(4L/I
Y\-xX:n.\
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) UrvUt$WO
{ dz9U.:C
sSiteURL= sURL; Z{0BH{23
sFilePath = sPath; 1}DA| !~
sFileName = sName; mg'q-G`\<
this.nSplitter = nSpiltter; c("|xe
oM~y8O
jn V=giBu
} |g3:+&
b/z-W`gw
ja_8n["z
public String getSSiteURL() ]WDmx$"&e
{ %Gh5!e:$SI
return sSiteURL; 6*9wGLE
} \QK@wgu
S"Cz. bv
Kt_oo[ey{
public void setSSiteURL(String value) +r8bGS]ki
{ &*<27-x
sSiteURL = value; A ]A{HEX
} ^r\rpSN
JkAM:,^(
vAUt~X"
public String getSFilePath() 13!@LbC
{ }~I!'J#)
return sFilePath; yQ[;y~W
} z5fE<=<X_W
njy2pDC@
:jl*Y-mM
public void setSFilePath(String value) C:J;'[,S
{ fkzSX8a9}
sFilePath = value; NZq-%bE
} ccuGM WG*
.c"nDCFVR
^}=)jLS
public String getSFileName() y d97ys
{ ]^~}/@
return sFileName; 2nB99L{6
} e,p"=/!aY
PdcIHN
o{s2T)2
public void setSFileName(String value) ,5n!a.T
{ }GB~3 J
sFileName = value; tUv>1) [
} 6ZQ |L=Ytp
QQ3<)i
>j5\J_(;D
public int getNSplitter() m+Ye`]
{ 7=6:ZSI
return nSplitter; q9/v\~m
} AFz:%m
s:U:Dv
_ >OP
public void setNSplitter(int nCount) ANhtz1Fl
{ K|P0nJT
nSplitter = nCount; Yr9'2.%Q
} y*i&p4Y*
} 2zBk#c+
J6Z[c*W
\]tBwa
/* @k?vbq
**Utility.java QHk\Z
*/ Dl;hOHvKk
package NetFox; ?,vLRq.
JmI%7bH@
7Q .Su
public class Utility { \zO.#H
*d1BpR%
kt6x"'"1
public Utility() rQjk
{ ]at$ohS
(g##wa)L
.<hHK|HF
} O*xx63%jR
7>Z|K
//线程睡眠 ')uYI;h9
public static void sleep(int nSecond) oPSPb(.
{ H%wB8Y ]
try{ Mg2+H+C~:
Thread.sleep(nSecond); ]&*POri&
} FZe/3sY
catch(Exception e) =z.j{%
{ G]K1X"W?
e.printStackTrace (); )pWgt5:7~
} oB:7R^a
} 1V%tev9a
jRK}H*uem
//日志 Y <6|z3
public static void log(String sMsg) R|st<P
{ 0@ `]m
System.err.println(sMsg); k%.v`H!
} }.&nEi`
clE9I<1v
VeA@HC`?"
public static void log(int sMsg) ^)AECn
{ V*p[6{U0
System.err.println(sMsg); ?JrUZXY
} HsCL%$k
} voa)V1A/]
O=0p}{3l
5GsmBf$RUb
/* TDh)}Ms
**TestMethod.java +IdM|4$\1
*/ {?qfH>oFA
package NetFox; }a]`"_i;[
|Xso}Y{
NQdwj>_a
public class TestMethod { x93@[B*%
o0H^J,6gV
<y6`8J7:
public TestMethod() PQHztS"
{ ///xx/weblogic60b2_win.exe -)V0D,r$[
try{ BZeEZ2"
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pzF_g-B
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); T\6Qr$t
SiteFileFetch fileFetch = new SiteFileFetch(bean); X`8<;l
fileFetch.start(); A(y6]E!
} 1-kuK<KR
catch(Exception e){e.printStackTrace ();} V3,C5KKk&z
9jal D X
Ia2WBs=
} e{)giJY9
z|g2Q#$-\S
49qa
public static void main(String[] args) e@'x7Zzh
{ \8{SQ%
new TestMethod(); lu#a.41
} mF6-f#t>H+
} x;mw?B[
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