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)); 7\*_/[B
} J6Uo+0S
for(int i=0;i<nEndPos.length-1;i++) *,g|I8?%VD
{ rUjK1A{V
nEndPos = nStartPos[i+1]; ]i'hCa $$
} Hts.G~~8
nEndPos[nEndPos.length-1] = nFileLength; rlSar$
} JR/:XYS+
} K=x>%6W7b
|^jl^oW
#"{wm
//启动子线程 N)Fy#6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; wi'CBfr'z
for(int i=0;i<nStartPos.length;i++) ,Bh!|H(?L1
{ "~~Js~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), JWhi*je
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), TR:V7d
nStartPos,nEndPos,i); df_hmkyj
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X yi[z tN
fileSplitterFetch.start(); PCzC8~t
} 7b7~D +b
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N"d M+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5Vo8z8]t`
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8,\toT7
nEndPos = " + nFileLength); hM~9p{O
// fileSplitterFetch[nPos.length-1].start(); 2pR+2p`
`I|$U)'
(V2~txMh
//等待子线程结束 K=|x"6\
//int count = 0; &NbhQY`k
//是否结束while循环 GSzb
boolean breakWhile = false; 7:7i}`O
bup)cX^
Db"jzMW.
while(!bStop) _;baZ-
{ yVQ0;h
write_nPos(); IC&>PwXb
Utility.sleep(500); (>O'^W\3p
breakWhile = true; P|,@En 1!
'Fi\Qk'D@
+&?#Gdb
for(int i=0;i<nStartPos.length;i++) ?.1yNO*s
{ #-S%aeB
if(!fileSplitterFetch.bDownOver) wLn,x;;<
{ M*M,Z
breakWhile = false; ykFm$ 0m+I
break; ]PWK^-4P
} )kLTyx2&
} K q;X(&Z
if(breakWhile) v@_}R_pX
break; D@9adwQb
)+;Xfftz
z ((Y\vP
//count++; ;S Re`
//if(count>4) (+SfDL$m
// siteStop(); e}%~S9\UL5
} #{-l(016y
*E$&
$07;gpZt
System.err.println("文件下载结束！"); HRX}r$
} X>}-UHKV+
catch(Exception e){e.printStackTrace ();} {4B{~Qe;
} CUIFKM
+<#0V!DM
Zy!^HS$
//获得文件长度 \0gU)tVZ
public long getFileSize() zx:Qz
{ u-v/`F2wN
int nFileLength = -1; L1P.@hJ
try{ n*twuB/P 1
URL url = new URL(siteInfoBean.getSSiteURL()); )1#J4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R@ksYC3 F
httpConnection.setRequestProperty("User-Agent","NetFox"); WC2sRv4]3
D^]g`V*N
p'SclH[
int responseCode=httpConnection.getResponseCode(); p7H0|>
if(responseCode>=400) | ]#PF*
{ IIj :\?r
processErrorCode(responseCode); 6"@`iY
return -2; //-2 represent access is error jL^3/0"o
} e,J q<=j
"d1~(0=6<m
Cp!bsasj
String sHeader; e`]x?t<U4/
k*xMe-
d v8q&_
for(int i=1;;i++) 2'>
{ JDbRv'F:(
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); P*=M?:Jb,
//Utility.log(in.readLine()); 2%!yV~Z
sHeader=httpConnection.getHeaderFieldKey(i); r.WQ6h/eZ5
if(sHeader!=null) &k\`!T1
{ Y)V)g9
if(sHeader.equals("Content-Length")) w|t}.u
{ MS7rD%(,'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); t4Q&^AC
break; Veeuw
} [2*?b/q3J
} _+B{n^ {
else l$1 ]
break; E@.daUoB
} 9E`Laf
} O0`o0!=P
catch(IOException e){e.printStackTrace ();} <m"fzT<"
catch(Exception e){e.printStackTrace ();} zDD
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}BFX7X
Utility.log(nFileLength); 7+'&(^c
zCz"[9k
gUa-6@
return nFileLength; bd'io O
} ZovF]jf k
g"}j
9-ei#|Vnt[
//保存下载信息（文件指针位置） c_~tCKAZ
private void write_nPos() nO#a|~-))
{ |K.J@zW
try{ NCX`-SLv
output = new DataOutputStream(new FileOutputStream(tmpFile)); x->H~/
output.writeInt(nStartPos.length); i>j(Dsv
for(int i=0;i<nStartPos.length;i++) `f)X!S2l
{ xR~9|H9a
// output.writeLong(nPos); ^55q~DP}>
output.writeLong(fileSplitterFetch.nStartPos); lZ'ZL*
output.writeLong(fileSplitterFetch.nEndPos); >~}}*yp
} I+GP`=\
output.close(); :|&S7&l]
} o;[cApiQ,2
catch(IOException e){e.printStackTrace ();} qk}Mb_*C)
catch(Exception e){e.printStackTrace ();} MkK6.qV\z
} prw% )#,
HrK7qLw7
+~n"@ /
//读取保存的下载信息（文件指针位置） /ka "YU
private void read_nPos() q.:j yj6
{ vp|.x |@
try{ uY;7&Lw y1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )u?^w
int nCount = input.readInt(); Xs Ey8V
nStartPos = new long[nCount]; J]ri|a
nEndPos = new long[nCount]; =WEWs4V5A
for(int i=0;i<nStartPos.length;i++) WF_24Mw
{ P;bOtT --
nStartPos = input.readLong(); wl Nl|+ K
nEndPos = input.readLong(); .VA'W16
} KN<KZM
input.close(); tq.g4X ;_
} :"Gd;~p.
catch(IOException e){e.printStackTrace ();} Sp-M:,H3H
catch(Exception e){e.printStackTrace ();} U6IvN@ g
} [M#I Nm}
SO+J5,)HA
JWsOze8#
private void processErrorCode(int nErrorCode) ALi3JU
{ undH{w=
System.err.println("Error Code : " + nErrorCode); u`gY/]y!
} N"Cd{3
h[& \OD,P
cnL@j_mb
//停止文件下载 g0M/Sv
public void siteStop() V8947h|&
{ Tqm)-|[
bStop = true; zwgO|Qg;
for(int i=0;i<nStartPos.length;i++) [pzo[0G 'v
fileSplitterFetch.splitterStop(); \= G8
mQ=nU
oTb4T=
} |>dqZ_)v
} ^K?Mq1"Db
//负责部分文件的抓取 9RQw6rL
**FileSplitterFetch.java JQ<9~J
*/ V\/5H~L
package NetFox; bnxR)b~
t}fU 2Yb
qwvch^?>FQ
import java.io.*; en8l:INX
import java.net.*; AkX8v66:
NGAjajB
3h4'DQ.g
public class FileSplitterFetch extends Thread { >mp"=Y
]cP$aixd
G]E-2 _t7
String sURL; //File URL MB"<^ZX
long nStartPos; //File Snippet Start Position /rzZU}3[
long nEndPos; //File Snippet End Position @YI-@
int nThreadID; //Thread's ID +<7a$/L?4
boolean bDownOver = false; //Downing is over lQt* LWd[
boolean bStop = false; //Stop identical (R^Ca7F
FileAccessI fileAccessI = null; //File Access interface a3B^RbDP&8
m ol|E={si
9UcSQ"D
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #TD0)C/
{ WXX08"
this.sURL = sURL; *6QmYq6c<
this.nStartPos = nStart; U,tWLX$@
this.nEndPos = nEnd; dL|*#e
nThreadID = id; !A#(bC
fileAccessI = new FileAccessI(sName,nStartPos);//定位 jB0ED0)wX
} t4FaU7
A>Xt 5vk+
>OW>^%\!1
public void run() `cpUl*Y=
{ l>?k>NEpP
while(nStartPos < nEndPos && !bStop) (a@}J.lL
{ #2Z\K>L
(6~~e$j
$|H7fn(r
try{ L<O"36R
URL url = new URL(sURL); $?dutbE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KO&oT#S
httpConnection.setRequestProperty("User-Agent","NetFox"); ]V.0%Ccw;.
String sProperty = "bytes="+nStartPos+"-"; DS>qth
httpConnection.setRequestProperty("RANGE",sProperty); XFrgnnt
Utility.log(sProperty); M|\C@,F]8
|s{[<;
|C3~Q{A
InputStream input = httpConnection.getInputStream(); {on+ ;,
//logResponseHead(httpConnection); >o8N@`@VK-
8\9s,W:5
t.6gyrV7><
byte[] b = new byte[1024]; N-<m/RS
int nRead; +I_p\/J?w/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) S#f}mb0,
{ 8L,i}hIo.
nStartPos += fileAccessI.write(b,0,nRead); YN($rAkL
//if(nThreadID == 1) 9/4Bx!~A
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FA#8
} Cl'3I%$8K
)+v'@]r
{, zg
Utility.log("Thread " + nThreadID + " is over!"); ;&U! g&
bDownOver = true; 1`l10fqU
//nPos = fileAccessI.write (b,0,nRead); WoX,F1o
} ~JSa]6:_+
catch(Exception e){e.printStackTrace ();} 1xt N3{c
} ZY{zFg9
} r^$WX@ t&
'(&,i/O
Ilv _.
//打印回应的头信息 _5SA(0D#9
public void logResponseHead(HttpURLConnection con) "%fvA;
{ =d`/BDD
for(int i=1;;i++) ui4*vjd
{ qFg"!w
String header=con.getHeaderFieldKey(i); YDdY'd`*
if(header!=null) e=w.7DSE
//responseHeaders.put(header,httpConnection.getHeaderField(header)); H/BU2sa
Utility.log(header+" : "+con.getHeaderField(header)); b8TwV_&|X
else dT4e[4l
break; ZX03FJL7u
} EE[JXoke
} \<4Hp_2?
fk
iJem9XXb
public void splitterStop() oar`xH$C
{ =EdLffU[J
bStop = true; v %GcNjZk5
} /8tF7Mmr
`Wy8g?d;bn
6<+8[o
} kr6^6I.
H_+F~P5RC
84UI)nE:Q
/* ?~s23%E
**FileAccess.java _M9-n
*//文件访问(定位，写) 7l|D!`BS
package NetFox; Lyj0$wbH`
import java.io.*; Ri&?uCCM
_$YT*o@0J
Y~ ( <H e?
public class FileAccessI implements Serializable{ #Hyfjj
2*9rhOK*
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ( R0>0f@
RandomAccessFile oSavedFile; sPUn"7
long nPos; cri.kr9Y
s u)AIvF{
k| Ye[GM*
public FileAccessI() throws IOException hY-;Vh0J
{ N>'|fNx]
this("",0); LAfv1
} T{Rhn V1
"f-z3kL
6pi^rpo
public FileAccessI(String sName,long nPos) throws IOException Z2wgfP`
{ f0,,<ib.w
oSavedFile = new RandomAccessFile(sName,"rw"); dJYQdo^X
this.nPos = nPos; ~Q/G_^U:
oSavedFile.seek(nPos); KW5u.phv
} Z_Z; g]|!
T6=q[LpsKN
%HK\
public synchronized int write(byte[] b,int nStart,int nLen) {Y#$
{ rS/}!|uAu
int n = -1; >:yU bo)
try{ hJcN*2\:
oSavedFile.write(b,nStart,nLen); x&PVsXdt5m
n = nLen; ,@*Srrw
} uY'77,G_J
catch(IOException e) i9%cpPrg8
{ fR6.:7&
e.printStackTrace (); %juR6zB%8
} F4%vEn\!
5v@-.p
jaq`A'o5
return n; K=`;D
} bPHqZ*f
Z 71.*
+bv-!rf
} 4fp]z9Y
GDUOUl&
bRzw.(k0`r
/* \L@DDK|"`6
**SiteInfoBean.java a1nj}1M%
*/ S66..sa
package NetFox; {~RS$ |
b\^q9fy
s wIJmA
public class SiteInfoBean { `[*nUdG
Yo$ xz
fqcFfz6?x
private String sSiteURL; //Site's URL ]sf1+3
private String sFilePath; //Saved File's Path aHvsgp]
private String sFileName; //Saved File's Name 3.^Tm+ C
private int nSplitter; //Count of Splited Downloading File ~-.^eT kP
+~~&FO2
m2o)/:
public SiteInfoBean() |`50Tf\J
{//nSplitter的缺省值为5 @&G< Np`
//default value of nSplitter is 5 ZC\&n4~7
this("","","",5); [c=T)]E1
} n6f
@h&crI[c
?UPZ49y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) KNw{\Pz~w
{ @Ht7^rz+S
sSiteURL= sURL; ub* j&L=
sFilePath = sPath; X\a*q]"_
sFileName = sName; c+^#(OB
this.nSplitter = nSpiltter; Pfv| K;3i
^bjaa
=oPc\VYW
} IV5B5Q'D
=]auP{AlE
|dxcEjcY_
public String getSSiteURL() 1 ynjDin<
{ T1&^IO-F7$
return sSiteURL; 3Wl,T5}{
} ]$VYzE2e
j.FW*iX1C
?tJyQT
public void setSSiteURL(String value) 2W_p)8t>b
{ DG!H8^
sSiteURL = value; S|pMX87R
} \~:Uj~
AUk,sCxd
;GgW&*|
public String getSFilePath() =QiVcw,G#
{ )t-Jc+*A>
return sFilePath; wf= s-C
} m<DiYxK
y ;$8C
WjrUns
public void setSFilePath(String value) 69o,T`B
{ ~baVS-v
sFilePath = value; mimJ_=]DC
} BV8-\R@
?1G7=R
79?%g=#=
public String getSFileName() lhk[U!>#
{ .|pyloL.
return sFileName; u6,NQ^4
} I,:R~^qJ8v
@DYxDap{
EPZ^I)
public void setSFileName(String value) FccT@,.F
{ .[E"Kb}=
sFileName = value; D]s8w
} x'.OLXx>
z`^DQ8+\j
z DP
public int getNSplitter() .)zX<~,
{ Wxi|(}
return nSplitter; 4K(AXk
} sU/R$Nbr
7HpfHqJ7
H</Mh*Fl2G
public void setNSplitter(int nCount) 99\;jz7
{ ?ep'R&NV
nSplitter = nCount; F>0[v|LG
} UA{tmIC\
} U%7| iK
~_z"So'|F_
nJvDkh#h1
/* Jf/X3\0N7
**Utility.java mv,<#<-W
*/ "K"]/3`k-
package NetFox; t~luBUF
%4%$NdU"
[^cflmV
public class Utility { 4rmSo^vK
Gl1Qbd0
7.r}98V
public Utility() ]$StbBP
{ cPemrNxydN
;}tEU'&
v[aFSXGj)
} Zewx*Y|
wQ7G_kVp
//线程睡眠 J< E"ZoY
public static void sleep(int nSecond) oPX `/X#
{ AF=9KWqf
try{ 3N'fHy
Thread.sleep(nSecond); 2f%G`4/p
} 6%p$C oR
catch(Exception e) )]=1W
{ FAS+*GFz
e.printStackTrace (); =9lrPQ]w
} 1;\A./FVv
} a^vXwY
#!m`A+!~!
//日志 8fn7!
public static void log(String sMsg) PjH[8:,
{ PFqc_!Pm
System.err.println(sMsg); "w)Y0Qq*z
} N(%%bHi#V
ii.L]#3y
DA/l`Pn
public static void log(int sMsg) "!9hcv-;
{ QW5S=7
System.err.println(sMsg); t3#My2=
} Z$0+jpG_s
} woHB![Q,
,_JhvPWR,)
V-y"@0%1
/* },"T,t#
**TestMethod.java ndSM*Fq
*/ JJ50(h)U
package NetFox; ]%{.zl!
x2#5"/~4
arCi$:-z@
public class TestMethod { 8sDbvVh1F
23lLoyN
x}g5
public TestMethod() B@:c8}2.
{ ///xx/weblogic60b2_win.exe +0w~Skd,
try{ a?zn>tx
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >q'xW=Y j\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3f u*{8.XZ
SiteFileFetch fileFetch = new SiteFileFetch(bean); ^J?ExMu
fileFetch.start(); hmA$gR_
} +<G |Ru-
catch(Exception e){e.printStackTrace ();} p19[qy~.
@>wD`<U|
j|`6[93MG
} @R5jUPUVV
kWF/SsE
*^BW[C/CTR
public static void main(String[] args) 6m.ChlO/
{ B!`Dj,_
new TestMethod(); P87!+pB(
} h>'9-j6B
} |WopsV %
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