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)); +*T7@1
} Dhw(#{N
for(int i=0;i<nEndPos.length-1;i++) UU mTOJr
{ $M lW4&a|
nEndPos = nStartPos[i+1]; Ax?y
} "UGY2skf;
nEndPos[nEndPos.length-1] = nFileLength; _w/EP
} D!NQ~'.a=2
} r(aLEJ"u?
6)-X
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//启动子线程 o( RG-$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (\a]"g,]v
for(int i=0;i<nStartPos.length;i++) wrbLDod /
{ Iw&vTU=2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {fF3/tL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?NR A:t(}
nStartPos,nEndPos,i); wF,UE_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); iH@yCNE"
fileSplitterFetch.start(); Y/>&0wj)d
} X4AyX.p
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZP*q4:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); sCis4gX.]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 2`>ToWN!
nEndPos = " + nFileLength); 9{}1r2xW
// fileSplitterFetch[nPos.length-1].start(); wEE\+3b)
#Jn_c0
?ROqn6k&c
//等待子线程结束 ~\.w^*$#Y
//int count = 0; ^3{TZ=_;|
//是否结束while循环 OK6]e3UO
boolean breakWhile = false; ;04Ldb1{|3
L ugn3+
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while(!bStop) `m>*d!h=
{ :x{NBvUIc
write_nPos(); 65p?Igb
Utility.sleep(500); #H{<gjs]
breakWhile = true; ( Qcp{q
Y/ee~^YxK'
`m?c;,\
for(int i=0;i<nStartPos.length;i++) qT"Q1xU[
{ Jd(,/q
if(!fileSplitterFetch.bDownOver) |8=nL$u
{ ,:`4%
breakWhile = false; a1.Ptf eW|
break; _$f9]bab
} \ 3?LqJ
} U,gti,IX^
if(breakWhile) ]dk8lZ;bo
break; YZ7|K<
kc @[9eV
zG9Y!SY\-
//count++; Q7$.LEioN
//if(count>4) @,u/w4
// siteStop(); h0-hT
} /D^"X 4!"
:GW&O /Yo
?)[EO(D
System.err.println("文件下载结束！"); }!/$M\w
} NqEA4C
catch(Exception e){e.printStackTrace ();} }_;!hdYq
} g'=B%eO$j:
Tp?y8r
x.zbD8l/9
//获得文件长度 dd%h67J2<
public long getFileSize() : G`hm{
{ DrBUe'RH:M
int nFileLength = -1; \ZhfgE8{%
try{ ~r$jza~o(
URL url = new URL(siteInfoBean.getSSiteURL()); $m+sNEAa
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); UIAj]
httpConnection.setRequestProperty("User-Agent","NetFox"); x-<)\L&
9Xl5@%uz?z
&jczO-R^
int responseCode=httpConnection.getResponseCode(); 6{+{lBm=y
if(responseCode>=400) _5m#2u51i
{ w'fT=v)
processErrorCode(responseCode); P*@2.#oO
return -2; //-2 represent access is error ~L_hZso4
} EV^~eTz
-gas?^`
=;|QZ"%E
String sHeader; FwY&/\J7V
f<*Js)k
]M[#.EX
for(int i=1;;i++) I}t3 p|z
{ 0zCw>wBPW
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); r"a5(Q;n
//Utility.log(in.readLine()); vZ N!Zl7S
sHeader=httpConnection.getHeaderFieldKey(i); f1)x5N
if(sHeader!=null) n?ctLbg
{ qYf |Gv
if(sHeader.equals("Content-Length")) ofMY,~w
{ U_$qi
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); bb`':3%
break; ;?~$h-9)
} )r z+'|,
} 1>Dl\czn
else 5"]~oPK
break; P"?FnTbv[
} -}4NT{E
} pge++Di
catch(IOException e){e.printStackTrace ();} ?@t d
catch(Exception e){e.printStackTrace ();} pD2<fP_
,7)C"
RQB]/D\BO
Utility.log(nFileLength); Gqcz<=/
kR@Yl Yo
G #T<`>T
return nFileLength; B_l{<
} m6yIR6H
8W+gl=C~
JwRF(1_sM
//保存下载信息（文件指针位置） `)h6j)xiQ
private void write_nPos() J~iBB~x.
{ p!V>XY'N^
try{ Z,;cCxE
output = new DataOutputStream(new FileOutputStream(tmpFile)); ror|R@;y
output.writeInt(nStartPos.length); %Lrd6i_j
for(int i=0;i<nStartPos.length;i++) Enq|Y$qm
{ J5[~LZKW
// output.writeLong(nPos); r-IVb&uFb
output.writeLong(fileSplitterFetch.nStartPos); qXW})(
output.writeLong(fileSplitterFetch.nEndPos); J.+BD\pa
} 8; R|
output.close(); z6~ H:k1G%
} XJ+6FT/qss
catch(IOException e){e.printStackTrace ();} %77p5ctW
catch(Exception e){e.printStackTrace ();} $RwB_F
} oi&Wo'DX
oM1 6C|
(zYy}g#n
//读取保存的下载信息（文件指针位置） NLe}Jqp
private void read_nPos() %=<IGce
{ (9mMkU=
try{ Y'3}G<'%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); asgF1?r
int nCount = input.readInt(); ]G}B 0u3
nStartPos = new long[nCount]; 's!-80sd
nEndPos = new long[nCount]; ExXM:1 e26
for(int i=0;i<nStartPos.length;i++) 0l#)fJo
{ RF!1oZ
nStartPos = input.readLong(); 9H]Lpi^OH
nEndPos = input.readLong(); =}fd6ea(o
} @C-dG7U.P
input.close(); Dli^2hD
} Ld,5iBiO:
catch(IOException e){e.printStackTrace ();} Hv<'dt$|
catch(Exception e){e.printStackTrace ();} 5;TuVU.8Q
} x2#qg>`l
XfzVcap
PaCzr5!~f
private void processErrorCode(int nErrorCode) _0 snAt^iC
{ >(tn"2
System.err.println("Error Code : " + nErrorCode); B)h>8 {
} Uo_tUp_Q
]Lqt(c
W:VP1 :
//停止文件下载 8{Fm[ %"
public void siteStop() t.hm9}UQ
{ Vjm_F!S
bStop = true; M}"r#Plq
for(int i=0;i<nStartPos.length;i++) 3%<C<(
fileSplitterFetch.splitterStop(); MuEy>dl
L1)@z8]
)I@L+
} cQZ652F9
} $\Tkhq<
//负责部分文件的抓取 VnJMmMM
**FileSplitterFetch.java "x&C5l}n
*/ z&3]%t `C
package NetFox; 1(GHCxA8G
A~{f/%8D
AzpV4(:an.
import java.io.*; $ 'QdFkOr
import java.net.*; ]&i+!$N_
7TX,T|>9
VLg EX4
public class FileSplitterFetch extends Thread { *Wb=WM-.
)yb+M ez
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String sURL; //File URL ;ggy5?>Qu
long nStartPos; //File Snippet Start Position x@cN3O
long nEndPos; //File Snippet End Position H.O(*Q=
int nThreadID; //Thread's ID [ij,RE7,T
boolean bDownOver = false; //Downing is over g>7Y~_}
boolean bStop = false; //Stop identical 22KI]$D#f
FileAccessI fileAccessI = null; //File Access interface jV7&Y.$zF]
gw3NS8 A+
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException eE/%6g
{ +ydm,aKk
this.sURL = sURL; WA.\*Nqze
this.nStartPos = nStart; 4W\,y_Qo
this.nEndPos = nEnd; ]Bb7(JX
nThreadID = id; mKg@W;0ML
fileAccessI = new FileAccessI(sName,nStartPos);//定位 02]xJo
} JFqf;3R
,i++fOnQ
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public void run() /'>;JF
{ !Zwf 397
while(nStartPos < nEndPos && !bStop) ]~a_d)
{ X#+`e+Df
h[ 6hM^n
H]qq ~bO[
try{ {B yn{?w
URL url = new URL(sURL); '%3{jc-}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LnMwx#^*
httpConnection.setRequestProperty("User-Agent","NetFox"); <qiICb)~
String sProperty = "bytes="+nStartPos+"-"; DB&SOe
httpConnection.setRequestProperty("RANGE",sProperty); hD 46@
Utility.log(sProperty); ! VRI_c
g^o_\hp
`.k5v7!o
InputStream input = httpConnection.getInputStream(); o|287S|$
//logResponseHead(httpConnection); 5&4F,v[zp
yCM{M
4&}\BU*
byte[] b = new byte[1024]; dB|Te"6
int nRead; a0zG(7.D
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) NR/-m7#-
{ |Odu4 Q
nStartPos += fileAccessI.write(b,0,nRead); +6%7CC6
//if(nThreadID == 1) l6B.6 '4)w
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T~Yg5J
} Cals?u#U=
B {i&~k
&9kiO
Utility.log("Thread " + nThreadID + " is over!"); rqvU8T7A
bDownOver = true; 6dT|;koWbm
//nPos = fileAccessI.write (b,0,nRead); f Lk"tW
} ~{ .,8jE
catch(Exception e){e.printStackTrace ();} [w%#<5h
} W:ixzpQ
} P6OM)>C
<J#R3{
gv` h-b
//打印回应的头信息 |z7dRDU}]
public void logResponseHead(HttpURLConnection con) c=t*I0-OVS
{ Z oTNm
for(int i=1;;i++) urxqek
{ w?ai,Pw
String header=con.getHeaderFieldKey(i); ~&[u]u[
if(header!=null) V/UB9)i+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;2W2MZ!TF
Utility.log(header+" : "+con.getHeaderField(header)); RUrymkHFB
else $u,GVq~
break; "=`~iXT{e
} 0e9A+&r
} w:tGPort
DM/hcY$MW
Y<ElJ>A2I
public void splitterStop() zlX!xqHj
{ p[P[#IeL
bStop = true; 7jZrU|:yu(
} )%|r>{
&kq7gCd
bf^ly6ml
} uf0^E3H
V9$-twhu
:A$wX$H01
/* M7H~;S\3IM
**FileAccess.java xucIjPi]
*//文件访问(定位，写) .%hQJ{vf-^
package NetFox; wR1K8b".DC
import java.io.*; wG6FS
k*9%8yi_ U
= P8~n2V
public class FileAccessI implements Serializable{ <\xQ7|e
I_L;T
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 $UmE
RandomAccessFile oSavedFile; |x[$3R1@
long nPos; h&'J+b
|=OpzCs
b2%blQgo
public FileAccessI() throws IOException {G]`1Q1DR
{ &*c'uNw
this("",0); Bzm.X=U:
} 8I {56$
H!^C2
u> In(7\
public FileAccessI(String sName,long nPos) throws IOException ^"/Dih\_
{ 9/QS0
oSavedFile = new RandomAccessFile(sName,"rw"); GfQ^@Tl
this.nPos = nPos; !%)L&W_
oSavedFile.seek(nPos); ]LY^9eK)>{
} V'$oTZ`
m4\g o
oYGUjI
public synchronized int write(byte[] b,int nStart,int nLen) )da:&F -
{ t)`+d=P
int n = -1; =z']s4
try{ i!ds{`d
oSavedFile.write(b,nStart,nLen); z'v9j_\
n = nLen; pJ$(ozV
} jS}'cm-
catch(IOException e) aliQ6_
{ FL~9</
e.printStackTrace (); !}C4{Bgt*
} _fe0,
CYMM*4#
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return n; [j1^$n 8V
} mKMGdN~
|4LQ\'N&
Xd5! Ti}
} &?fvt
c[6zX#{`
lP-kZA!
/* orK+B4
**SiteInfoBean.java SSo~.)J
*/ TosPk(o(
package NetFox; {!>E9Px
=54Vs8.
)OS>9 kFH
public class SiteInfoBean { C!oksI
Udg& eEF
YGi/]^Nba
private String sSiteURL; //Site's URL B1up^(?
private String sFilePath; //Saved File's Path o4U]lK$
private String sFileName; //Saved File's Name 0fZ:")&4,
private int nSplitter; //Count of Splited Downloading File a'o}u,e5
,OFq'}q
w@4t$bd7
public SiteInfoBean() oT$(<$&<
{//nSplitter的缺省值为5 jw2_!D
//default value of nSplitter is 5 lsN/$M|}
this("","","",5); ]Sk#a-^~
} | 3hT{
$a)JCErN
hG< a
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :K!GR
{ (0Zrfu^
sSiteURL= sURL; `,hW;p>-
sFilePath = sPath; 5>0\e_V
sFileName = sName; 0]/,m4a#n
this.nSplitter = nSpiltter; 5?S{W
&T5fH!?4
[]sB^UT
} s,{RP0|
Y8{T.\%\+
>}xAg7\^
public String getSSiteURL() w50.gr7
{ I%.jc2kK
return sSiteURL; & bp#1KR)
} ~m009
f]{1ZU%4
/7!_un9
public void setSSiteURL(String value) >;T$#LZ
{ "P>$=X~Zi
sSiteURL = value; ym-lT|>Z
} YqK+F=0
-PIA;#Gs
HMl!?%%
public String getSFilePath() )M&I)In'
{ Wo<PmSt9i
return sFilePath; ir( -$*J
} S&;T_^|
{Zd)U "
.x\/XlM
public void setSFilePath(String value) P'FPe55F
{ ;p?42rCIcl
sFilePath = value; BWqik_
} [MSDk"o&
ZEXj|wC
+8?R+0P
public String getSFileName() o`JlXuG?o
{ vfk7J5y
return sFileName; c,{&
} sM);gI14
+aXMHT"U
=DQdPA\K
public void setSFileName(String value) ly[\mGr
{ wh7i G8jCz
sFileName = value; YFC0KU
} M+;!]tbc3
Q8M:7#ySji
w|K(>5nz
public int getNSplitter() 5Tcl<Y6l
{ [TpA26#TTO
return nSplitter; tDuUAI54
} [E..VesrM
xC=3|,U
E@'CU9Fo
public void setNSplitter(int nCount) d=.n|rS4 W
{ jN5} 2 p*
nSplitter = nCount; ;OT#V,}r
} 8E.5k@
} *1 J#Mdd
->RF`SQu
nEa'e5 lg
/* +0JH"L5!
**Utility.java Pv/%s) &y&
*/ )0 42?emn
package NetFox; pRDON)$
leX7(Y;!a7
GakmROZ@9
public class Utility { qQ?,|4)y
*BP\6"X
oto wvm
public Utility() zwniS6R1
{ k8t Na@H
0W<nE[U
hD9'`SQ
} X&;]
$ uIwRG <
//线程睡眠 BSq;RG(
public static void sleep(int nSecond) ys"mP*wD
{ x:&L?eOT
try{ c+G:@%
Thread.sleep(nSecond); a_}BTkfHa
} VES4x%r=
catch(Exception e) D/%b@Ls2ze
{ IZ(CRKCGBl
e.printStackTrace (); $M8>SLd
} dBD4ogo1
} \qK}(xq[
+%cr?g
//日志 f>, Qhl
public static void log(String sMsg) *M\i4FO8
{ l7r N
System.err.println(sMsg); ]@j"0F/`
} =[tls^
QWQ6j#`
X0r#,u
public static void log(int sMsg) Stp*JU
{ { P\8g8
System.err.println(sMsg); r+W8m?oi
} 9rvxp;
} KohQ6q
5yN8%_)T
eABdye
/* Xy(SzJ%
**TestMethod.java D*2p
*/ $d"f/bRWy
package NetFox; 1069]
qKb-aP-
rsIPI69qJ.
public class TestMethod { C,e$g
,+5VeRyrV
#+DmH
public TestMethod() (A<sFw?
{ ///xx/weblogic60b2_win.exe 0tm "kzy
try{ 2KNKdV3NK
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); HBf8!\0|/
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~9ls~$+*
SiteFileFetch fileFetch = new SiteFileFetch(bean); F8r455_W"
fileFetch.start(); ?0)XS<
} sZP3xh[B
catch(Exception e){e.printStackTrace ();} `F`'b)
W/F4wEODY
^1& LHrT
} k2,oyUT=S
Dqcu$V]
..]X<
public static void main(String[] args) qYiK bzy
{ XTXo xZ#w
new TestMethod(); N(/<qv
} :W<,iqSCm
} ^3@a0J=F
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