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)); +H:}1sT;n
} DHg)]FQ/
for(int i=0;i<nEndPos.length-1;i++) (:P#l&f
{ A("\m>g$b
nEndPos = nStartPos[i+1]; ?[]jJ
} wP7 E8'
nEndPos[nEndPos.length-1] = nFileLength; =pZ$oTR
} X2|&\G9c
} \3&1iA9=)
6d`qgEM3
XXw>h4hl
//启动子线程 NQxx_3*4O
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; D GL=\
for(int i=0;i<nStartPos.length;i++) wg+[T;0S
{ j#~ S"t
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ov<vSc<u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), O7]kcA
nStartPos,nEndPos,i); An_3DrUFV_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KVevvy)W
fileSplitterFetch.start(); 2]y Hxo/6
} \[G"/]J
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;qO3m-(d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); c|@OD3w2lM
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", X?YT>+g;
nEndPos = " + nFileLength); % *ng *
// fileSplitterFetch[nPos.length-1].start(); 'l<Oj&E
:-_"[:t 5Z
-_xTs(;|8
//等待子线程结束 SP\s{,'F-b
//int count = 0; ;VzdlCZ@
//是否结束while循环 _?]W%R|
boolean breakWhile = false; |!81M|H
U2r[.Ru
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while(!bStop) riF-9 %i
{ PWeWz(]0Z4
write_nPos(); j u&v4]
Utility.sleep(500); t33\f<e
breakWhile = true; n%;4Fm?
s{OV-H
`z`=!1
for(int i=0;i<nStartPos.length;i++) `,O"^zR)z
{ VnqcpJ
if(!fileSplitterFetch.bDownOver) ?E,-P!&R
{ Scug wSB
breakWhile = false; Q,M,^_
break; r0wAh/J|
} d;,Jf*x\
} _%3p&1ld
if(breakWhile) XqU0AbQ
break; FJqg,
Sz:PeUr9h
+f$ {r7
//count++; 1,:QrhC
//if(count>4) ,k1ns?i9KH
// siteStop(); p-m\0tQ
} iMv):1p>8
D^xg2D
\x<,Ma=D
System.err.println("文件下载结束！"); QL @SE@"
} &lID6{79Z
catch(Exception e){e.printStackTrace ();} g##<d(e!}
} nXk9 IG(
~]24">VZf
\irKM8]LJ
//获得文件长度 gil:SUW1r
public long getFileSize() ecx_&J@D
{ /3.;sS]B
int nFileLength = -1; 7yJE+o'
try{ l*(L"]
URL url = new URL(siteInfoBean.getSSiteURL()); BUdO:fr
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); } @ [!%hE
httpConnection.setRequestProperty("User-Agent","NetFox"); AQtOTT$
2kOaKH[(q
k{'<J(Hb
int responseCode=httpConnection.getResponseCode(); OJ7Uh_;/
if(responseCode>=400) L8Q/!+K
{ o6RT4`
processErrorCode(responseCode); x[fp7*TiG
return -2; //-2 represent access is error 7L!}F;yT
} 0$NzRPbH
roPC ^Q
PT~F^8,)
String sHeader; me F.
QCG-CzJ9l
gV$0J?Pr.
for(int i=1;;i++) N A_8<B^
{ c6 .j$6t
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Zl>wWJ3y
//Utility.log(in.readLine()); {t4':{Y+
sHeader=httpConnection.getHeaderFieldKey(i); 3DxgfP%n
if(sHeader!=null) WZjR^6
{ oCLM'\
if(sHeader.equals("Content-Length")) <(~Wg{
{ vXZP>
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ADM!4L(s4}
break; P8H2v_)X&
} l: kW|
} B qINU
else w11L@t[5W8
break; O>I%O^
} +3M1^:
} ?v-!`J>EF#
catch(IOException e){e.printStackTrace ();} {u0sbb(
catch(Exception e){e.printStackTrace ();} @\:@_}Z`_}
S;/pm$?/
!]9qQ7+R%
Utility.log(nFileLength); tR4+]K
>p#_L^oZ%
zo8&(XS
return nFileLength; *=]UWM~]
} [S-#}C?~
;\f0II3
+;)Xu}
//保存下载信息（文件指针位置） bdvpH DA
private void write_nPos() WRRR"Q$
{ o.Bbb=*rZ
try{ D(&Zq7]n
output = new DataOutputStream(new FileOutputStream(tmpFile)); D><^7nr%
output.writeInt(nStartPos.length); 6-\' *5r
for(int i=0;i<nStartPos.length;i++) zGc]*R
{ 9 &Ry51
// output.writeLong(nPos); -<AGCiLz
output.writeLong(fileSplitterFetch.nStartPos); dj4a)p|YN
output.writeLong(fileSplitterFetch.nEndPos); GO*D4<#u
} In;P33'p
output.close(); XF>!~D
} 5Q:49S47
catch(IOException e){e.printStackTrace ();} t\PSB
catch(Exception e){e.printStackTrace ();} >6W#v[
} 7Bd=K=3u
n 4cos
D(Q]ddUi'
//读取保存的下载信息（文件指针位置） naA8RD5/
private void read_nPos() sO!m,pK(
{ |9BX ~`{
try{ _;/+8=
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); +bR|;b(v
int nCount = input.readInt(); 1.<gC
nStartPos = new long[nCount]; ;>fM?ae5
nEndPos = new long[nCount]; biForT_no
for(int i=0;i<nStartPos.length;i++) ;TK$?hrv*1
{ *(XGNp[0
nStartPos = input.readLong(); bPkz=^-
nEndPos = input.readLong(); pB]*cd B?
} T11>&K)
input.close(); Q~n%c7
} _KBa`lhE
catch(IOException e){e.printStackTrace ();} \/nSRAk
catch(Exception e){e.printStackTrace ();} -G'3&L4 D
} cXr_,>k
I"QU{]|J
``@e7~F{
private void processErrorCode(int nErrorCode) ccx0aC3@I
{ bj_/
System.err.println("Error Code : " + nErrorCode); 'geN dx
} /%F,
I>6zX
m;TekJXm
//停止文件下载 W&[-QM8
public void siteStop() gR_Exs'K
{ w'y,$gtX/
bStop = true; k!x`cp
for(int i=0;i<nStartPos.length;i++) g706*o)h
fileSplitterFetch.splitterStop(); g5x>}@ONq7
<(xro/
'F:Tv[qx
} gNkBHwv
} Fiw^twz5
//负责部分文件的抓取 3Tc90p l*t
**FileSplitterFetch.java Gv[(0
*/ ~zvZK]JoX
package NetFox; G_WHW(8
W@%g_V}C*
o3NB3@uj<
import java.io.*; `=Bv+
import java.net.*; mtw{7E
IJ:JH=8
EN,}[^Z
public class FileSplitterFetch extends Thread { -zzT:C
2E!Q5 l!j
nQg_1+
String sURL; //File URL LY#V)f
long nStartPos; //File Snippet Start Position Q)8I(*
long nEndPos; //File Snippet End Position H:WuMwD4
int nThreadID; //Thread's ID RXu`DWN
boolean bDownOver = false; //Downing is over 9C!b f \
boolean bStop = false; //Stop identical <^942y-=
FileAccessI fileAccessI = null; //File Access interface N| P?!G-=
V?jWp$
[o7Qr?RN
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =+[`9
{ F[)tg#}@G
this.sURL = sURL; "5EL+z3v
this.nStartPos = nStart; 6?JvvS5
this.nEndPos = nEnd; v_pFI8Cz)
nThreadID = id; 0xaK"\Q
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Sogt?]HB$
} `_]UlI_h
8.7lc2aX
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public void run() ~\<L74BB
{ 6['o^>\}f
while(nStartPos < nEndPos && !bStop) S/l6c P
{ MlW*Tugg
g;7u-nP
>McEuoZx9
try{ 5dbj{r)s6i
URL url = new URL(sURL); QNxxW2+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); K(P.i^k
httpConnection.setRequestProperty("User-Agent","NetFox"); w02C1oGfx
String sProperty = "bytes="+nStartPos+"-"; 5v=e(Ph+
httpConnection.setRequestProperty("RANGE",sProperty); @Q&k6.{4Z
Utility.log(sProperty); H7meI9L
g+(Y)9h&
&^Gp
InputStream input = httpConnection.getInputStream(); F%O+w;J4
//logResponseHead(httpConnection); <,U$Y>
mHH>qW{`
Fr(;C>
byte[] b = new byte[1024]; f9)0OHa
int nRead; 1xO-tIp/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) YlR9 1LX
{ r$x;rL4
nStartPos += fileAccessI.write(b,0,nRead); 7mtg
//if(nThreadID == 1) {.e^1qE
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hZ"Sqm]
} 0JqvV
[h8macx
vY,D02EMw
Utility.log("Thread " + nThreadID + " is over!"); ;Sp/N4+
bDownOver = true; .SNg2.
//nPos = fileAccessI.write (b,0,nRead); C\^,+)Y\~
} IlB*JJnl
catch(Exception e){e.printStackTrace ();} .Sv/0&O
} @18}'k
} l 3 jlKB
\: B))y?}d
Q5sJ|]Bc
//打印回应的头信息 Q-1Xgw!
public void logResponseHead(HttpURLConnection con) azO7C*_
{ *55unc
for(int i=1;;i++) n8`WU3&
{ D#^euNiWd
String header=con.getHeaderFieldKey(i); u*rHKZ9i
if(header!=null) &)_ z!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); I8YCXh
Utility.log(header+" : "+con.getHeaderField(header)); x+DecO2
else cIrc@
break; k~fH:X~x
} }XqC'z
} dQO5
U\-R'Z>M
rZ2cC#
public void splitterStop() _6g(C_m'T?
{ P>03 DkbB
bStop = true; b #Llu$
} Lg|d[*;'7
/w2-Pgm-[\
,lFp4C
} *M$'dLn
tk>J mcTw
91nw1c!
/* 9`M7 -{
**FileAccess.java @rF|WT
*//文件访问(定位，写) :H+8E5
package NetFox; MIh\z7gW
import java.io.*; z<.?8bd
)lq+Gv[%F
ntW1 )H'o
public class FileAccessI implements Serializable{ S,Tc\}
Aq\K N.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 $+$l?2
RandomAccessFile oSavedFile; P]armg%
long nPos; M+:9U&>
!%.=35NS@E
i6g=fx6j*
public FileAccessI() throws IOException v-/vj/4>
{ $dA]GWW5A
this("",0); ]b:>7_la
} 9Hd_sNUu\
y*p02\)
1+YqdDqQ
public FileAccessI(String sName,long nPos) throws IOException P+QL||>L
{ syI|gANT/r
oSavedFile = new RandomAccessFile(sName,"rw"); 8(L6I%k*
this.nPos = nPos; 8;#yXlf
oSavedFile.seek(nPos); NFR>[L V
} \N$)Q.M
$g/h=w@
B&6lG!K'?
public synchronized int write(byte[] b,int nStart,int nLen) uL^`uI#I
{ 7!\zo mx
int n = -1; |=MhI5gsx
try{ e6^}XRyf
oSavedFile.write(b,nStart,nLen); ml /S|`Drk
n = nLen; c] t@3m
} h_SkX@"/-
catch(IOException e) II!~"-WH
{ 0=K8 nxdx
e.printStackTrace (); MH9vg5QKp
} +_+j"BT
g4952u
=itQ@``r
return n; / :6|)AW.{
} e[0"x.gu
`csZ*$7
ga(k2Q;y
} *ZxurbX#
yc`*zLWh
q6<P\CSHy<
/* P,F eF'J^
**SiteInfoBean.java -4P `:bF
*/ o{^`Y
package NetFox; KHgn
d ez4g
5;,h8vW
public class SiteInfoBean { "/mtuU3rt
D/GE-lq
Aa4Tq2G
private String sSiteURL; //Site's URL j4+Px%sW
private String sFilePath; //Saved File's Path JodD6;P
private String sFileName; //Saved File's Name Ks@cwY
private int nSplitter; //Count of Splited Downloading File ;_2+Y^Qb
QR_h#N2h
;BYuNQr
public SiteInfoBean() I~&9c/&
{//nSplitter的缺省值为5 ?r@^9
//default value of nSplitter is 5 qZ&~&f|>e
this("","","",5); v^vi *c
} 4d-(:
egURRC!
v"Ax'()
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `E?0jQ
{ x~wS/y
sSiteURL= sURL; 14jN0\
sFilePath = sPath; G$%F`R[
sFileName = sName; .Y"F3 R
this.nSplitter = nSpiltter; 32j}ep.*
/zoy,t-i
ai-rF^ehC
} t(9q6x3|e
"H<us?r{
k)|.<
public String getSSiteURL() ;i'[c`
{ Z7RBJK7|.
return sSiteURL; :GO"bsjL
} LO>42o?/i
%dv?n#Uf
M +r!63T
public void setSSiteURL(String value) R&J?XQ
{ }v4dOGc?
sSiteURL = value; 7B (%2
} (Bd'Pj]:
K +3=gBU*w
Dfa3&##{
public String getSFilePath() ?%}!_F`h%
{ #/f~LTE
return sFilePath; _#s,$K#
} 8/BMFRJ
pDSNI2
D fzsA4
public void setSFilePath(String value) \6JOBR
{ UL{J%Ze=~
sFilePath = value; Xq&BL,lS
} 46Sz#^y P
{G VA4=UAE
]|+M0:2?
public String getSFileName() 9|#cjHf
{ kuV7nsXiQ
return sFileName; ``Q6R2[|)
} ;'= cNj
kMMgY?
$i5J}
public void setSFileName(String value) W>)0=8#\
{ mpMAhm:
sFileName = value; (rkg0
} X3X_=qzc
]p3f54!
+ovK~K$A
public int getNSplitter() wz*iwd-
{ (Y@T5-!D
return nSplitter; $?G@ijk,
} |f#hGk6
pX?3inQP%(
-6HwGfU
public void setNSplitter(int nCount) xI{4<m/0N
{ q`b6if"
nSplitter = nCount; Z,A$h>Z
} dQ.#8o=
} \`2'W1O
t'l4$}(
MmR6V#@:
/* r(46jV.sD:
**Utility.java L2ydyXIsd
*/ _y_}/
package NetFox; {YzCgf
czuIs|_K*
[eDrjf3m
public class Utility { MMs~f*
.4)oZ
!S#3mT-
public Utility() 4JAz{aw'b
{ .qO4ceW2-~
{_-kwg{"(
uK2HtRY1
} {E:`
gM\>{ihM'
//线程睡眠 D=TS IJ@
public static void sleep(int nSecond) SG&,o=I$
{ ir_XU/ve
try{ a(~Y:v
Thread.sleep(nSecond); q[,p#uJ]
} yu6{6[
catch(Exception e) O -1O@:}c
{ J**(7d
e.printStackTrace (); ~v.mbh
} jtP*C_Scv/
} <\~v$=G
,PTM'O@aU#
//日志 *9^8NY]
public static void log(String sMsg) ahg:mlaob
{ A'DFY {
System.err.println(sMsg); I)Xf4FS@
} ]P0%S@]
gEd A hfx
,Vhve'=*2
public static void log(int sMsg) ?e$&=FC0;
{ g X!>ef
System.err.println(sMsg); x#D%3v"l_*
} p"ZvA^d\
} nF<K84
uL`#@nI
SIJ7Y{\.
/* f+cb83}n]
**TestMethod.java QxYm3x5
*/ t0m;tb bg
package NetFox; q? '4&
"GO!^ZG]
eU1F7LS
public class TestMethod { ez,.-@O
hCcI]#S&
/iU<\+ H
public TestMethod() w}xA@JgQ%
{ ///xx/weblogic60b2_win.exe @7twe;07r
try{ `Nx@MPo
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Z7a@$n3h
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .9nqJ7]
SiteFileFetch fileFetch = new SiteFileFetch(bean); yE8D^M|g
fileFetch.start(); !kovrvM6F
} .xJ54Vz
catch(Exception e){e.printStackTrace ();} K%v:giN$l`
d`^3fr'.4A
J:@gmo`M;V
} )D+BvJ Y"
$ZM'dIk?
#n>U7j9`O
public static void main(String[] args) .G{cx=;
{ 3K &637
new TestMethod(); W{F)YyR{.
} z9aR/:W}
} |]?f6^|4
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