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)); 9%>GOY
} xEt".K
for(int i=0;i<nEndPos.length-1;i++) l6^IX0&p
{ f;<qGM.#|
nEndPos = nStartPos[i+1]; 4{?Djnh
} 3g!tk9InG
nEndPos[nEndPos.length-1] = nFileLength; UADD 7d
} oe<9CK:?>
} :J|t! `
F]e]
=-XI)JV#
//启动子线程 0{0|M8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ')kn
for(int i=0;i<nStartPos.length;i++) o1x IGP<
{ Tw|cgB
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3<ikMUq&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7B@[`>5?%L
nStartPos,nEndPos,i); 1'c
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0_d,sC?V
fileSplitterFetch.start(); )/BI:)
} `N8?F3>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NwH`t#zd
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); s8,{8k
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", YGRv``(
nEndPos = " + nFileLength); ][b_l(r$?
// fileSplitterFetch[nPos.length-1].start(); !a"RHg:HO
0^l|W|.Z
Tx)X\&ij&
//等待子线程结束 %d<uOCf\Q
//int count = 0; Bvke@|]kW
//是否结束while循环 F!FXZht$P
boolean breakWhile = false; 1bW[RK;GE
=|)W#x9=
2&st/y(hs
while(!bStop) %#!pAUP\&
{ F9DY\EI
write_nPos(); 9[<,49
Utility.sleep(500); }cov"o
breakWhile = true; 6\MH2&L<
YzTmXwuA5
+8tdAw
for(int i=0;i<nStartPos.length;i++) g. V6:>,
{ mez )G|
if(!fileSplitterFetch.bDownOver) E^uWlUb{
{ !+qy~h
breakWhile = false; h,:8TMJRRN
break; de.!~%D
} uWs5+
} 8*sZ/N.
if(breakWhile) y'ZRoakz)
break; h^{D "
Z)RoFD1]C
%O$4da"y
//count++; &&Sl0(6x[T
//if(count>4) bERYC|
// siteStop(); ^j"*-)R
} yQkj4v{
dA;f`Bi;Q
q&.SB`
System.err.println("文件下载结束！"); yqdhLX|Mk
} 7x *]
catch(Exception e){e.printStackTrace ();} !<psK[
} o<\CA[
TCW[;d
.}QR~IR'
//获得文件长度 gAcXd<a0
public long getFileSize() X@$x(Zc
{ jl# )CEx
int nFileLength = -1; Yb57Xu
try{ AL #w
URL url = new URL(siteInfoBean.getSSiteURL()); Rk#@{_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F1skI _!
httpConnection.setRequestProperty("User-Agent","NetFox"); *KF-q?PBb
0QE2e'}}-
n@9*>DU
int responseCode=httpConnection.getResponseCode(); E9=a+l9
if(responseCode>=400) xngK_n
{ $_N<! h*\
processErrorCode(responseCode); 1:I47/
return -2; //-2 represent access is error Y<X,(\iEHP
} l`s_Id#
9Ra_[1
n !ty\E
String sHeader; L_Q1:nL-0
X|Gsf= 1S
e<_p\LiOS
for(int i=1;;i++) ocwh*t)<k
{ Eeemy*U
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); vAW+ ,Rfj
//Utility.log(in.readLine()); _KSYt32N
sHeader=httpConnection.getHeaderFieldKey(i); N :E7rtT,M
if(sHeader!=null) &r\pQ};
{ VH3j
if(sHeader.equals("Content-Length")) fL[(;KcAa
{ n GE3O#fv
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8+5-7)
break; we6']iaV
} b<UZDyN~
} ]ee%=+'
else gie}k)&M
break; X9^a:7(
} &M$s@FUY
} O9>&E;`5
catch(IOException e){e.printStackTrace ();} t\2Lo7[Pu
catch(Exception e){e.printStackTrace ();} 1n7tmRl
qV57P6<
x%kS:!
Utility.log(nFileLength); $j(2M?.>#
q.L0rY!
#S+GI!
return nFileLength; Z_&6<1,H
} " $5J7
y>zPsc,
%zg&eFRHI
//保存下载信息（文件指针位置） 31b9pi}nf
private void write_nPos() /JPyADi
{ 0w?\KHT
try{ 't3/< h<
output = new DataOutputStream(new FileOutputStream(tmpFile)); YKbR#DC\
output.writeInt(nStartPos.length); ;5 W|#{I
for(int i=0;i<nStartPos.length;i++) a%Ky;ys
{ &f1dCL%z7
// output.writeLong(nPos); d,j"8\@
output.writeLong(fileSplitterFetch.nStartPos); $0rSb0[
output.writeLong(fileSplitterFetch.nEndPos); A!}Wpw%(/
} :~JgB
output.close(); \N1G5W
} (Sc]dH
catch(IOException e){e.printStackTrace ();} )ymd#?wq
catch(Exception e){e.printStackTrace ();} JCNZtWF
} kb>:M.
Yv!%Is
6AgevyVG
//读取保存的下载信息（文件指针位置） BwO^F^Pr?k
private void read_nPos() hamn9
{ <6k5nEh
try{ ol^J-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); P@LYa_UFsN
int nCount = input.readInt(); 56(S[
nStartPos = new long[nCount]; XBv:$F.>$
nEndPos = new long[nCount]; M/ @1;a@\
for(int i=0;i<nStartPos.length;i++) Nq>74q]}n8
{ Ct[{>asun
nStartPos = input.readLong(); xcO Si>
nEndPos = input.readLong(); m_~!Lj[u.
} :Mr_/t2(
input.close(); xk=5q|u_-
} r=[T5,L(s
catch(IOException e){e.printStackTrace ();} T1ZAw'6(K
catch(Exception e){e.printStackTrace ();} wPTXRq%
} 9j458Yd4*
tiJY$YqA
MH|!tkW>:
private void processErrorCode(int nErrorCode) )24r^21.q
{ `mV&[`NZ
System.err.println("Error Code : " + nErrorCode); +5(#~
} B5"(NJ;
!%n3_tZC
|<&9_Aq_
//停止文件下载 ,yW BO
public void siteStop() w4Nm4To
{ [h7nOUL!
bStop = true; CSx V^
for(int i=0;i<nStartPos.length;i++) U1<EAGo|
fileSplitterFetch.splitterStop(); ]v7f9MC'\
+ZeHZjd
'Dyt"wfo
} ?<c)r~9]
} } y@pAeS,
//负责部分文件的抓取 8"R;axeD
**FileSplitterFetch.java 1t{h)fwi
*/ e_6VPVa
package NetFox; t-gg,ttnA
p b:mw$XQ7
zSMNk AM
import java.io.*; Ndq|Hkd
import java.net.*; ML?%s`
?qwTOi
cA_77#<8
public class FileSplitterFetch extends Thread { V,?i]q;5
{Lu-!}\NP
`MFw2nu@t
String sURL; //File URL :JW!$?s8H
long nStartPos; //File Snippet Start Position B:dk>$>uQ
long nEndPos; //File Snippet End Position ! 9B| `
int nThreadID; //Thread's ID [80jG+6
boolean bDownOver = false; //Downing is over 9dl\`zlA*
boolean bStop = false; //Stop identical -?gr3rV@
FileAccessI fileAccessI = null; //File Access interface lNuZg9h
s"b()JP
Z_{`$nW
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1qXqQA
{ ^Nl)ocHv!
this.sURL = sURL; *x3";%o
this.nStartPos = nStart; $PA=7`\MP/
this.nEndPos = nEnd; ;Hr FPx&d1
nThreadID = id; |UvM[A|+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /Y:1zLs%
} p.,o@GcL~
qUX
L|4kv
public void run() !HyPe"`oL
{ 6@kKr
while(nStartPos < nEndPos && !bStop) 4Eh 2sI
{ ?eD,\G
5^lroC-(x
j&n][=PL
try{ vq yR aaMf
URL url = new URL(sURL); ~_v?M%5i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |&vQ1o|}
httpConnection.setRequestProperty("User-Agent","NetFox"); | _/D-m*
String sProperty = "bytes="+nStartPos+"-"; [V'3/#Z
httpConnection.setRequestProperty("RANGE",sProperty); tpw0j CVu
Utility.log(sProperty); &>kklP
a86m?)-c
FtbqZN[
InputStream input = httpConnection.getInputStream(); \,jrug<C$^
//logResponseHead(httpConnection); j.O7-t%C
T;D`=p#
$P#Cf&R
byte[] b = new byte[1024]; WK5~"aw
int nRead; 6kH47Yc?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) F?=(4Pyvu
{ V*P3C5l
nStartPos += fileAccessI.write(b,0,nRead); 7e$\|~<
//if(nThreadID == 1) (3YqM7cqt
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F#S^Q`
} qGG
J{8_4s!Xt>
yIC.JmD*
Utility.log("Thread " + nThreadID + " is over!"); R=ddQ:W6g
bDownOver = true; P~nI6/r1
//nPos = fileAccessI.write (b,0,nRead); ]eA<
} (XYYbP
catch(Exception e){e.printStackTrace ();} @a,X{0
} `c@KlL*!Q
} ^/`:o}7K7
J5Rr7=:*S
DE3>F^ j
//打印回应的头信息 [oN}zZP]
public void logResponseHead(HttpURLConnection con) K|$Dnma^n
{ ^)=c74;;
for(int i=1;;i++) ]UyIp`nV;
{ ?Pz:H/$
String header=con.getHeaderFieldKey(i); l/[0N@r~
if(header!=null) %jEdgD%xV
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }5dYmny
Utility.log(header+" : "+con.getHeaderField(header)); QW :-q(s
else SrzlR)
break; a x1
} U1(<1eTyu
} (9q61zA
.lrI|BH?z
W,Q"?(+]B
public void splitterStop() AP.WTFf
{ %0 (,f
bStop = true; j~!0n[F
} 3c] oU1GfF
.zr2!}lB
\wRbhN
} wWm1G)
=mV1jGqX
8XtZF,Du
/* =1g
**FileAccess.java q:Gi Qk-
*//文件访问(定位，写) ^44AE5TO
package NetFox; =KJK'1m9
import java.io.*; w^N xR,
`btw*{.[
vH_QSx;C#
public class FileAccessI implements Serializable{ nW2fB8yq
[B3qZ"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 K~**. NF-n
RandomAccessFile oSavedFile; D*3\4=6x
long nPos; *44^M{ti<
l]RO'
01Bs7@"+
public FileAccessI() throws IOException ,aS6|~ac4
{ u )+;(Vd
this("",0); >-rDBk ;K
} )M(;:#le
v,w/g|
'J~{8w,.
public FileAccessI(String sName,long nPos) throws IOException C;2!c
{ O-- "\4
oSavedFile = new RandomAccessFile(sName,"rw"); ?H8w/{J
this.nPos = nPos; Dg~r%F
oSavedFile.seek(nPos); gaBt;@?:Q
} -;=0dfC(
tWL3F?wd
\/,54c2
public synchronized int write(byte[] b,int nStart,int nLen) Q" BIk =
{ 8 PI>Q
int n = -1; nWpqAb
try{ /h'V1zL#
oSavedFile.write(b,nStart,nLen); =N,9#o6^
n = nLen; xe}d&
} [)U|HnAJ
catch(IOException e) ~PYMtg=i
{ 5D0O.v
e.printStackTrace (); `Q?rQ3A}
} S'T&`"Mr
Cv{>|g#
0g% `L_e_
return n; B6&PYMFK?*
} ^qXc%hjg
'5zolp%St
oiYI$ql3L
} fR<_4L
>?K@zsv}
F VBuCi?W
/* "O1\]"j
**SiteInfoBean.java "w] Bq0
*/ R,[dEP
package NetFox; lN$#lyy
Dd8*1,
$p@V1"x
public class SiteInfoBean { 6|gC##T
@,0W(
W/COrgbW
private String sSiteURL; //Site's URL LwIl2u*
private String sFilePath; //Saved File's Path ?)<DEu:Y
private String sFileName; //Saved File's Name ^(7<L<H
private int nSplitter; //Count of Splited Downloading File !4zSE,1
Dz$GPA
U{(B)dFTH
public SiteInfoBean() urmx})=
{//nSplitter的缺省值为5 !v(j#N< m
//default value of nSplitter is 5 C5mq@$6
this("","","",5); SQ7Ws u>T@
} 7i?"akr4
ximW!y7
b4%sOn,
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) csP 5R3
{ ?m5@ 635
sSiteURL= sURL; 2(V;OWY(@
sFilePath = sPath; xu9K\/{7
sFileName = sName; SYkLia(Ty
this.nSplitter = nSpiltter; v|Y:'5`V
`7<4]#b^o
m'D_zb9+
} Y?Ph%i2E
?HT+| !4p
';"W0
public String getSSiteURL() %D|p7&
{ ,r\
return sSiteURL; O ;,BzA-n
} :%ms6j/B&V
* S4IMfp
1fwjW0t
public void setSSiteURL(String value) ]6)^+(zU
{ "w3#2q&
sSiteURL = value; pC<~\RR
} 1FC'DH!
A/eZnsk
07pASZ;~
public String getSFilePath() ( <~
{ *`.h8gTD,
return sFilePath; bHx09F]
} r}>8FE9S'H
1&%6sZN
"b)Y5[nW
public void setSFilePath(String value) vsc)EM ]
{ .f)&;Af^
sFilePath = value; !,8jB(
} dqd:V$o
z|,YO6(L
LLp/ SWe
public String getSFileName() /[ _aw&W}Z
{ ^2C)Wk$
return sFileName; -1'O
} hKa<9>MI`
kY d'6+m
:iW+CD)j
public void setSFileName(String value) ~*aPeJ
{ F91uuSSL
sFileName = value; f|U;4{k
} s|*0cK!K^
cE(P^;7D
9i+OYWUO
public int getNSplitter() Wp7lDx
{ M*XAyo4fI
return nSplitter; -J7BEx
} ?#N: a
kn2s,%\`<p
[6+iR
public void setNSplitter(int nCount) +XL^dzN[|$
{ p5RnFe l
nSplitter = nCount; KO*# ^+g
} z$#q'+$
} 5q<cZ)v#&
NXwthc3
Y#aL]LxZE
/* }_,\yC9F
**Utility.java T!-*;yu
*/ <%d/"XNg[D
package NetFox; |"}F cS y
Vf28R,~m
MR")
public class Utility { rw:z|-r
B49: R>
6-"@j@l5<
public Utility() Vr/UY79
{ (2 nSZRB
Q,pnh!.-c
"==fWf
} =rL%P~0wq
W4MU^``
//线程睡眠 `<Ry_}V
public static void sleep(int nSecond) EJAk'L+nuH
{ ANIx0*Yl(
try{ Ax"]+pb
Thread.sleep(nSecond); @4)NxdOE
} >* Ag0.Az
catch(Exception e) <Zb~tYp
{ eyM<#3\\S
e.printStackTrace (); /x2-$a:<
} =&%}p[ 3g
} Nuc;Y
\mK;BWg)
//日志 aMU0BS"
public static void log(String sMsg) Gm`#0)VC
{ zWs("L(#s
System.err.println(sMsg); h7r*5E
} }4Q~<2
3?%?J^/a
]1Wh3C
public static void log(int sMsg) <8J_[ S
{ 9w)W|9
System.err.println(sMsg); oz.#+t%X$b
} #uRj9|E7
} _'Jz+f.
}dv$^4 *n
6&J7=g%G
/* t,bQ@x{zVC
**TestMethod.java >O;V[H2[
*/ X}V}%
package NetFox; 9~7s*3zI
0|i3#G_~
)~X.x"}8k
public class TestMethod { jw 4B^2}
WilKC|R]P
I$0O4
public TestMethod() ?Yf0h_>
{ ///xx/weblogic60b2_win.exe mJU1n
try{ 4Tdp;n\F
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Mg"e$m
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,1K`w:uhS
SiteFileFetch fileFetch = new SiteFileFetch(bean); _O,k0O
fileFetch.start(); Q[n*ce7L0
} }Fq~!D Ee
catch(Exception e){e.printStackTrace ();} f(Su
e 48N[p
>TQNrS^$J
} s~p(59
;_~9".'<d
>0X_UDAWz
public static void main(String[] args) [r#m +R"N
{ f>CJ1;][{
new TestMethod(); ;% <[*T:*'
} K[q{)>,9
} |tr^ `Z
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