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)); pft-.1py
} :Y Ki
for(int i=0;i<nEndPos.length-1;i++) +# 3e<+!F
{ '.wb= C
nEndPos = nStartPos[i+1]; |->CI
} tE#;$Ss
nEndPos[nEndPos.length-1] = nFileLength; \^1S:z
} hXh nJ
} Ae[fW97
4a=QTq0p
aka)#0l .
//启动子线程 akFT 0@9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7^7Jh&b)/
for(int i=0;i<nStartPos.length;i++) #U(kK(uO
{ hv`I`[/J
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 63i&<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Ms#rvn!J
nStartPos,nEndPos,i); p,.6sk
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); aJQzM
fileSplitterFetch.start(); suS[P?4
} @THa[|(S
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PJYUD5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); wF9L<<&B
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", O6ph_$nt.
nEndPos = " + nFileLength); ~F^tLi!5
// fileSplitterFetch[nPos.length-1].start(); M1icj~Jr
PIAE6,*
ed2r<H$
//等待子线程结束 !QpOrg
//int count = 0; /9=r.Vxh
//是否结束while循环 \zcR75
boolean breakWhile = false; as(/ >p
l8khu)\n4R
la}cGZ; p.
while(!bStop) fy$?~Ji&
{ Eq%f`Qg+1E
write_nPos(); .1}1e;f-
Utility.sleep(500); 84!Hd.H
breakWhile = true; UiVGOQq
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:dqZM#$d
for(int i=0;i<nStartPos.length;i++) Gj?$HFa
{ 6?Kl L [~
if(!fileSplitterFetch.bDownOver) inFS99DKx
{ l/,la]!T
breakWhile = false; qW`?,N)r
break; @C<ofg3E
} &)jq3
} \1SC:gN*#
if(breakWhile) i),bAU!+m
break; ap8q`a{j^
4l7 Ny\J
K iEmvC
//count++; d@p#{ -
//if(count>4) Wb>;L@jB7
// siteStop(); 1_b*j-j
} 14"+ctq
7{]dh+)
i)'tt9f$
System.err.println("文件下载结束！"); p="0Y<2l
} J?dLI_{<
catch(Exception e){e.printStackTrace ();} v<t?t<|J
} e_|Z&
4i PVpro
KIcIYCBz
//获得文件长度 Z+u.LXc|c
public long getFileSize() qvLh7]sbK:
{ yVgC1-8i*
int nFileLength = -1; KIi:5Y
try{ "g)V&Lx#X
URL url = new URL(siteInfoBean.getSSiteURL()); \ @fKKb|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xr{Ym99E$
httpConnection.setRequestProperty("User-Agent","NetFox"); aU~?&]
E%DT;1
3%bhW9H%
int responseCode=httpConnection.getResponseCode(); ] j8bv3
if(responseCode>=400) 4y#XX[2Wj
{ -pIz-*
processErrorCode(responseCode); `IEA
return -2; //-2 represent access is error haY]gmC
} _-lE$ O
Aj|->Y
|g.CS$'#Nt
String sHeader; |iI dm
bU}v@Uk
x\U[5d
for(int i=1;;i++) x1?mE)n]
{ _U}vKm
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .1q}mw
//Utility.log(in.readLine()); hHhDs>tB
sHeader=httpConnection.getHeaderFieldKey(i); p#{y9s4h
if(sHeader!=null) J8!2Tt
{ Q#G xo
if(sHeader.equals("Content-Length")) i6KB\W2
{ m$_b\^we
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); J_h.7V
break; I8YUq
} -iS^VzI|I
} tj'~RQvO
else ROmmak(y8
break; lKw-C[
} B,cFvS
} 4~&3.1
catch(IOException e){e.printStackTrace ();} |$b8(g$s)
catch(Exception e){e.printStackTrace ();} y]0O"X-G
GdcXU:J /
>x JzV
Utility.log(nFileLength); !8[T*'LJ-
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`hZh}K^
return nFileLength; 9xO@_pkX
} M2|!,2
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AU3Rz&~
//保存下载信息（文件指针位置） [B#XA}w
private void write_nPos() 0\{dt4nW&O
{ fj;ZGbg-O
try{ OemY'M?ZQ
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0-S.G38{
output.writeInt(nStartPos.length); |y[I!JdR
for(int i=0;i<nStartPos.length;i++) V:GypY)
{ ewU*5|*[
// output.writeLong(nPos); ?W{+[OXs
output.writeLong(fileSplitterFetch.nStartPos); XZ~kXE;B(
output.writeLong(fileSplitterFetch.nEndPos); .Pponmy
} Ba@~:
output.close(); Q $}#&
} \0x>#ygX
catch(IOException e){e.printStackTrace ();} XZb=;tYo
catch(Exception e){e.printStackTrace ();} o6px1C:
} @T~XwJ~
y\Aa;pL)RQ
Tc/^h4xH
//读取保存的下载信息（文件指针位置） 12z!{k7N
private void read_nPos() oj - `G
{ le\-h'D
try{ *,4rYb7I w
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); pE&G]ZC
int nCount = input.readInt(); Vml 6\X
nStartPos = new long[nCount]; >)u;X
nEndPos = new long[nCount]; D{6y^@/
for(int i=0;i<nStartPos.length;i++) `P;r[j"
{ }bv+^#
nStartPos = input.readLong(); PPB/-F]rr
nEndPos = input.readLong(); !iKW1ks
} ID2->J
input.close(); ~tA ^[tK
} 5[jcw`
catch(IOException e){e.printStackTrace ();} .oyAi||
catch(Exception e){e.printStackTrace ();} P|<V0 Vs.
} "00j]e.
P!W%KobZ7|
7P+1W \
private void processErrorCode(int nErrorCode) a#=d{/ab
{ Y7.+ Ma#|
System.err.println("Error Code : " + nErrorCode); x 4+WZYv3
} YWK0.F,8a
=U3S"W %
;[}OZt
//停止文件下载 f%,S::%Ea
public void siteStop() \Nt 5TG_
{ y>y2,x+[
bStop = true; ?Ts]zO%%Z
for(int i=0;i<nStartPos.length;i++) T;92M}\
fileSplitterFetch.splitterStop(); uaF-3
K<e #y!
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} R%WY!I8C
} KMj\A d
//负责部分文件的抓取 }#FV{C]
**FileSplitterFetch.java v`Jt+?I
*/ wHj1+W
package NetFox; 9 8|sWI3B
o1ZVEvp
jg710.v:
import java.io.*; tTy!o=
import java.net.*; 5v)^4( )
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r >'tE7W9
public class FileSplitterFetch extends Thread { Zo<)r2|O.
<a"(B*bBd
>[;W~*
String sURL; //File URL -wXeue},>
long nStartPos; //File Snippet Start Position Mp`$1Ksn
long nEndPos; //File Snippet End Position &u2;S?7m
int nThreadID; //Thread's ID ,p d-hu
boolean bDownOver = false; //Downing is over GQtNk<?$I
boolean bStop = false; //Stop identical i!%bz
FileAccessI fileAccessI = null; //File Access interface tn5%zJ#+
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]3O&8,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /*qRbN
{ TmG);B}
this.sURL = sURL; 7%Y`j/
this.nStartPos = nStart; 2t\0vV2)/O
this.nEndPos = nEnd; [Arf!W-QG
nThreadID = id; a<<4gXx
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]@#9B>v=
} ^v;)6a2
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public void run() ^cYB.oeu
{ %]4Tff
while(nStartPos < nEndPos && !bStop) ,m=G9QcN
{ EB[T 5{
)q=F_:$
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try{ m.K cTM%j
URL url = new URL(sURL); 9r?Z'~,Za
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )dkU4]
httpConnection.setRequestProperty("User-Agent","NetFox"); VmqJMU>.
String sProperty = "bytes="+nStartPos+"-"; qdix@@
httpConnection.setRequestProperty("RANGE",sProperty); l(Rn=?
Utility.log(sProperty); uyWheR
b(0<,r8
.$&^yp
InputStream input = httpConnection.getInputStream(); G,)zn9X
//logResponseHead(httpConnection); S~Gse+*
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XQy`5iv
byte[] b = new byte[1024]; /pj[c;aO
int nRead; J~2SGXH)^?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~m6=s~Vn
{ gK rUv0&F
nStartPos += fileAccessI.write(b,0,nRead); Z mJ<h&
//if(nThreadID == 1) n~ *|JJ*`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nQiZ6[L
} ?8-Am[xH
;M3%t=KV
]>X_E%`G<b
Utility.log("Thread " + nThreadID + " is over!"); `dZ|Ko%k
bDownOver = true; .TGw+E1k
//nPos = fileAccessI.write (b,0,nRead); (DiduSJ
} )=5&Q
catch(Exception e){e.printStackTrace ();} Pu3oQDldV
} [~9UsHfH
} O52/fGt
x"b'Pmw
DG;7+2U
//打印回应的头信息 C8-7XQ=B:b
public void logResponseHead(HttpURLConnection con) oai=1vt@
{ |oPRP1F-;e
for(int i=1;;i++) N9w"Lb
{ w)EYj+L
String header=con.getHeaderFieldKey(i); (uC8M,I\
if(header!=null) fu5L)P^T
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]}v]j`9m%
Utility.log(header+" : "+con.getHeaderField(header)); b}K,wAx
else y#GHmHeh
break; Cy;UyZ
} OH t)z.
} i\sBey ND"
>bW=oTFz
T-] {gc
public void splitterStop() ?Lg(,-:
{ KwL_ae6fV
bStop = true; d/; tq
} cw<IL
*z~,|DQ(A
Cab.a)o
} \BnU?z
F rckA
& P-8_I
/* *JJ8\R&P0
**FileAccess.java jYp!?%!
*//文件访问(定位，写) ?%6oM
package NetFox; {+67<&g
import java.io.*; ~IhM(Q*mO!
m]n2wmE3n
.!o]oM U/
public class FileAccessI implements Serializable{ J0!V(
1B;2 ~2X
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RcYUO*
RandomAccessFile oSavedFile; Rl ]x:
long nPos; IJ Jp5[w
E{\CE1*
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public FileAccessI() throws IOException gC1LQ!:;Oi
{ OijuOLt
this("",0); h3@tZL#g
} ~q ^o|?
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jqaX|)8|$
public FileAccessI(String sName,long nPos) throws IOException m'"r<]pB*4
{ Skt-5S#
oSavedFile = new RandomAccessFile(sName,"rw"); ,U\s89
this.nPos = nPos; $?56 i4
oSavedFile.seek(nPos); n4{%M
} ~(R=3
5 bI:xL}
K%J?'-
public synchronized int write(byte[] b,int nStart,int nLen) -.h)CM@L
{ vD#U+
int n = -1; (=!At)O
try{ {[!<yUJ`S#
oSavedFile.write(b,nStart,nLen); ,`HweIq(
n = nLen; t.( `$
} n#">k%bD
catch(IOException e) E;a,].
{ T~E;@weR
e.printStackTrace (); " aG6u^%
} ( cs
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jSp&\Wjb
return n; uRb48Qy2
} ]yPK}u
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Eg)24C R 4
} (%B{=w}8
`H! (hMMV
?,pwYT0g
/* NTu|cX\R
**SiteInfoBean.java j=O+U_w
*/ T1d@=&0"
package NetFox; vFk@
. Vb|le(7
@[;'b$T$
public class SiteInfoBean { 64u(X^i
G=cRdiy`C
%E_Y4Oe1
private String sSiteURL; //Site's URL +@rFbsyJ.
private String sFilePath; //Saved File's Path 5=?P6I_$G
private String sFileName; //Saved File's Name hQ|mow@Zmz
private int nSplitter; //Count of Splited Downloading File 5k0iVpjQ
_m9k2[N!
"B3jq^
public SiteInfoBean() AY52j
{//nSplitter的缺省值为5 IS]A<}j/-
//default value of nSplitter is 5 HUx`RX0>
this("","","",5); b=EI?XwJ
} !P{ /;Q
|Y!^E %*
cNd&C'/N
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `Q*`\-8J
{ JQKXbsXS
sSiteURL= sURL; F7<mm7BGZ
sFilePath = sPath; }eLApFHEDg
sFileName = sName; RW&o3_Ua
this.nSplitter = nSpiltter; <SNr\/aCRi
*F( qg%1+
'UX^]
} eX$KH;M
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public String getSSiteURL() c[-N A
{ 7rdmj[vu
return sSiteURL; Nr*l3Z>LD
} LgF?1?
"pDU v^ie
2 ,nhs,FZ
public void setSSiteURL(String value) Ic&~iqQ
{ uj3`M9
sSiteURL = value; #2^0z`-\_z
} F${sEtH
WXxnOLJr
2Z{?3mAb;
public String getSFilePath() 4XAB_Q
{ j55_wx@cA
return sFilePath; ajycYk9<m
} }uDpf0;^
F$8:9eL,T
bhUE!h<
public void setSFilePath(String value) &n1Vv_Lb
{ Y^]n>X
sFilePath = value; o`CM15d*7o
} RFbf2s\t
"[ S[vkI
x;W!sO@$
public String getSFileName() qXtC7uNj$
{ cpk\;1&t
return sFileName; =Z.0-C>W
} ?eTZ>o.p/
}C @xl9S"
[7><^?t V
public void setSFileName(String value) diXWm-ZKL
{ #f(a,,Uu'
sFileName = value; "7sv@I_j
} BQfnoF
QI[WXxp
uT]$R
public int getNSplitter() c%5P|R~g]p
{ f_ MK4
return nSplitter; q#j[0,^ $
} ?sHZeWZ(
g}`g>&l5
"vk]y
public void setNSplitter(int nCount) %scw]oF
{ Vn_&q6Pa
nSplitter = nCount; ?*V\ -7jg
} 1V`-D8-?
} mZU L}[xf
5"h4XINZ
6KGT?d
/* -|'@:cIZ
**Utility.java -Jd7
*/ Z+V%~C1
package NetFox; i@:^b_
-$!r+4|q
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public class Utility { | K|AUI
y3j$?oM
nOyG7:
public Utility() JA{kifu0+
{ 1!1,{\9%
RV@B[:
(w-"1(
} K cex%.
*ssw`}yE'
//线程睡眠 C1AX
public static void sleep(int nSecond) uNy-r`vg
{ ->qRGUW
try{ JRBz/ j
Thread.sleep(nSecond); +_ehzo97
} 12i`82>;
catch(Exception e) r7VBz_Q
{ ]|F`;}7
e.printStackTrace (); Eet/l]e#a
} =0&XdxX
} H.?`90IQ
4r;le5@
//日志 pKXSJ"Xo
public static void log(String sMsg) \ MuKS4
{ #HL$`&m
System.err.println(sMsg); ZWGelZP~
} b w1s?_P
{31X
)[Rwc#PA;
public static void log(int sMsg) G l/3*J
{ 2G|}ENC
System.err.println(sMsg); )2"WC\%
} @}jg5}
} yq, qS0Fo
&T-:`(
"viZ"/~6
/* 8;~,jZ s
**TestMethod.java W' Y<iA
*/ {B=64,D^7R
package NetFox; YeJTB}
`!N.1RP _
Wv5=$y
public class TestMethod { >mQD/U
a%y*e+oM
NjS<DzKhK
public TestMethod() {<IHiB35q
{ ///xx/weblogic60b2_win.exe K4Ed]hX
try{ e]1)_;b*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Dg^s$2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \B 8j9
SiteFileFetch fileFetch = new SiteFileFetch(bean); &: LE]w
fileFetch.start(); W SvhC
} ;t N@
catch(Exception e){e.printStackTrace ();} v3~`1MM
r *N@%T
6I~M8Lo;
} M+-odLltw
`-s]dq
|@rf#,hTDp
public static void main(String[] args) XR=ebl
{ b7'A5]X
new TestMethod(); cooicKS7
} *W=1yPP
} {'P?wv
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