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)); U]9k,#
} WZP1g kX&M
for(int i=0;i<nEndPos.length-1;i++) b?,=|H
{ QNxxW2+
nEndPos = nStartPos[i+1]; K(P.i^k
} Ht]O:io`
nEndPos[nEndPos.length-1] = nFileLength; 5v=e(Ph+
} @Q&k6.{4Z
} H7meI9L
g+(Y)9h&
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//启动子线程 K `A8N
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; X/m~^
for(int i=0;i<nStartPos.length;i++) ^f,%dM=i=
{ Blj<|\igc
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1xO-tIp/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), YlR9 1LX
nStartPos,nEndPos,i); %u2",eHCB
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4[Wwm
fileSplitterFetch.start(); ][YC.J
} ft4hzmuzM
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /bo`@ !-#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); mrr -jo
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", mMO]l(a&
nEndPos = " + nFileLength); FchO 6O
// fileSplitterFetch[nPos.length-1].start(); Az:A,;~+,!
8q:# '
:sAUV79M
//等待子线程结束 A8:eA
//int count = 0; VssWtL
//是否结束while循环 K}'?#a(aX=
boolean breakWhile = false; +Y$EZL.A
IA`Lp3Z
_c}# f\ +_
while(!bStop) E@AV?@<sc
{ J=HN~B1
write_nPos(); 0F 2p4!@W
Utility.sleep(500); >&^jKfY
breakWhile = true; @3S:W2k
SzfMQ@~
_sY; dS/
for(int i=0;i<nStartPos.length;i++) &)_ z!
{ 1y,/|Y
if(!fileSplitterFetch.bDownOver) 3UUN@Tx
{ >gz8,&
breakWhile = false; [X>f;;h
break; POX{;[SV
} 4Tb"+Y}
} \5Y<UJKi
if(breakWhile) da@W6Ovx
break; 2(Aw
GR_caP
n9-WZsc1
//count++; @Y}G,i
//if(count>4) e0<O6
// siteStop(); nyBT4e
} Zq5~M bldh
9\0$YY%
T8yMaC
System.err.println("文件下载结束！"); io@f5E+?
} fVdu9 l
catch(Exception e){e.printStackTrace ();} eo.B0NZsF
} ,zxv>8Nt
\Pe+]4R-Xo
P4+PY 8
//获得文件长度 b/ h#{'
public long getFileSize() rj4R/{h
{ w6pXF5ur>
int nFileLength = -1; ff~1>=^
try{ ~qK/w0=j
URL url = new URL(siteInfoBean.getSSiteURL()); \)ZCB7|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }<*KM)%
httpConnection.setRequestProperty("User-Agent","NetFox"); tf[)| /M
3Vak C
QX-n l~
int responseCode=httpConnection.getResponseCode(); ru4M=D
if(responseCode>=400) b`F]oQ_*
{ 2.MY8}&WBu
processErrorCode(responseCode); 2. v<pqn
return -2; //-2 represent access is error >`0mn|+
} $dA]GWW5A
Ba**S8{/`
2waPNb|
String sHeader; ydAiH*>
|--Jd$ dj
+(^HL3
for(int i=1;;i++) l,zhBnD
{ 8)ng> l
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?nWzJ5w3
//Utility.log(in.readLine()); |68k9rq
sHeader=httpConnection.getHeaderFieldKey(i); 5HIQw9g6
if(sHeader!=null) vo%"(!
{ S5d
if(sHeader.equals("Content-Length")) DJAKF
{ ?Dn}
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Y*S:/b~y
break; g4952u
} BRM!g9
} ]hoq!:>M1
else 0G0(g,3p
break; k[,0kP;
} AWKJ@&pA9m
} G=SMz+z
catch(IOException e){e.printStackTrace ();} %l6E0[
catch(Exception e){e.printStackTrace ();} 9C0#K\
iq[IZdza
1ANb=X|hig
Utility.log(nFileLength); vm'ZA7f6
N"suR}9%
9y<h.T
return nFileLength; 1X&jlD?
} 6U.|0mG[
$*T?}r>
| L1+7
//保存下载信息（文件指针位置） $mh\`
private void write_nPos() Iy&,1CI"]
{ 0U H]
try{ RZ;s_16GQ
output = new DataOutputStream(new FileOutputStream(tmpFile)); c?u*,d) G
output.writeInt(nStartPos.length); S(?A3 H
for(int i=0;i<nStartPos.length;i++) B?- poB&
{ u6Lx3
// output.writeLong(nPos); =:]v~Ehq
output.writeLong(fileSplitterFetch.nStartPos); S#$Kmm |
output.writeLong(fileSplitterFetch.nEndPos); ??U/Qi180
} aWJj@',_
output.close(); |_>^vW1f
} 7GWOJ^)
catch(IOException e){e.printStackTrace ();} Q2uV/M1?
catch(Exception e){e.printStackTrace ();} I.GoY[u_%
} |ns?c0rM
/of K7/
$(Mz@#%
//读取保存的下载信息（文件指针位置） ovBmo2W/
private void read_nPos() (Bd'Pj]:
{ tiHR&v
try{ ?%}!_F`h%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "\KBF
int nCount = input.readInt(); $|.8@ nj
nStartPos = new long[nCount]; kFV, Fg
nEndPos = new long[nCount]; V3cKbk7~
for(int i=0;i<nStartPos.length;i++) yxo=eSOM
{ Jk6}hUH,
nStartPos = input.readLong(); n2hV}t9O
nEndPos = input.readLong(); 6CIzT.
} ~IS8DW$;
input.close(); va'F '|
} $i5J}
catch(IOException e){e.printStackTrace ();} }$4z$&
catch(Exception e){e.printStackTrace ();} %kjG[C
} d%"XsbO
y{>f^S<
Xa?O)Bq.
private void processErrorCode(int nErrorCode) ,7]hjf_h
{ yy7(')wKO
System.err.println("Error Code : " + nErrorCode); '=n?^EPE3
} N+rU|iMa.
g-~ _gt7
D5D *$IC
//停止文件下载 K+F"VW*?
public void siteStop() 2 HEU
{ yXJ25Axb
bStop = true; ExS5RV@v'
for(int i=0;i<nStartPos.length;i++) )ffaOS!\
fileSplitterFetch.splitterStop(); JhFbze>
:^v Q4/,
{E:`
} iM)K:L7d
} <$0is:]
//负责部分文件的抓取 pg4W?N`
**FileSplitterFetch.java f +{=##'0
*/ O -1O@:}c
package NetFox; IMH4GVr"
vSH,fS-n
0\P5=hD)K
import java.io.*; HcsVq+
import java.net.*; .d]/:T -0
A'DFY {
%N*[{j= ^
public class FileSplitterFetch extends Thread { c$Kc,`2m7
)8@-
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String sURL; //File URL ?e$&=FC0;
long nStartPos; //File Snippet Start Position -3{Q`@F
long nEndPos; //File Snippet End Position ^ `y7JXI:
int nThreadID; //Thread's ID k&ci5MpN
boolean bDownOver = false; //Downing is over a)QT#.
boolean bStop = false; //Stop identical | ys5.|
FileAccessI fileAccessI = null; //File Access interface Q)DEcx-|,
.gx^L=O:
yV(#z2|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "?NDN4l*
{ n1."Qix0
this.sURL = sURL; eiKY az
this.nStartPos = nStart; R| ?Q&F_$
this.nEndPos = nEnd; (p-q>@m
nThreadID = id; >^s2$@J?p
fileAccessI = new FileAccessI(sName,nStartPos);//定位 MXaFqK<Y
} .xJ54Vz
wk|+[Rl;L
4=L>
public void run() jIubJQR~
{ 6e-ME3!<l
while(nStartPos < nEndPos && !bStop) >n"0>[:4
{ 3ZXAAV
>dl5^
XIInI
try{ J4T"O<i$58
URL url = new URL(sURL); :#YC_ id
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .4zzPD$1
httpConnection.setRequestProperty("User-Agent","NetFox"); J!uG/Us
String sProperty = "bytes="+nStartPos+"-"; Hr?lRaV
httpConnection.setRequestProperty("RANGE",sProperty); d%7?913
Utility.log(sProperty); 9\Jc7[b
MB)<@.A0
xt^1,V4Ei~
InputStream input = httpConnection.getInputStream(); ]Dq6XR
//logResponseHead(httpConnection); A9xeOy8e
}~ D WB"
`K{}
byte[] b = new byte[1024]; I3Vu/&8f|
int nRead; ^*ZaqMA
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |+ F ~zIu'
{ mw"FQ?bJ
nStartPos += fileAccessI.write(b,0,nRead); $JY\q2
//if(nThreadID == 1) XoKgs,y4
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); HMd?`
} cGV%=N^BE<
w%])
5A0]+)5E8
Utility.log("Thread " + nThreadID + " is over!"); Hu|Tj<S
bDownOver = true; jEBn"]\D
//nPos = fileAccessI.write (b,0,nRead); u@_|4Bp,"
} rI$NNk'A
catch(Exception e){e.printStackTrace ();} _&-d0'+
} |4@cX<d.
} z*},N$2=
p<L7qwOii
%0Ur3
//打印回应的头信息 ]9YA~n\
public void logResponseHead(HttpURLConnection con) IWo'{pk
{ mx9vjWfy
for(int i=1;;i++) JBpV'_"]
{ fu!T4{2
String header=con.getHeaderFieldKey(i); PNm@mC_fh
if(header!=null) \TP$2i%W
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /9_%NR[
Utility.log(header+" : "+con.getHeaderField(header)); 38w^="-T
else D\Ez~.H
break; chICc</l&
} /r7xA}se^
} )BJkHED{
l= {Y[T&
&{j!!LL
public void splitterStop() -E}X`?WhD
{ dXTD8 )&
bStop = true; `4K|L6
} Wc@ ,#v
;.4y@?B
f\R_a/Us
} )WoH>D
B?BOAH
^SpQtW118
/* =2$( tXL
**FileAccess.java LuySa2,
*//文件访问(定位，写) kN/YnY*J<
package NetFox; uGZGI;9f4
import java.io.*; |3~m8v2-
RG'iWA,9m`
[!)HWgx
public class FileAccessI implements Serializable{ 1J[$f>%n]
$I9&cNPv
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Cf(WO-F^
RandomAccessFile oSavedFile; # `^nmC/F
long nPos; 3@":&
M-t9M~
@XJ7ff&
public FileAccessI() throws IOException lrJV"H
{ Pm%xX~H
this("",0); /0\g!29l<
} ~u%$ 9IhM
3zB'AG3b
WVR/0l&bU
public FileAccessI(String sName,long nPos) throws IOException a{xJ#_/6
{ qy'-'UlIr
oSavedFile = new RandomAccessFile(sName,"rw"); kl]V_ 7[
this.nPos = nPos; ,ciX *F"
oSavedFile.seek(nPos); c!E{fSP
} *+rfRH]a
AO5&Y.A#
|tAkv
public synchronized int write(byte[] b,int nStart,int nLen) XYvj3+
{ anSZWQ
int n = -1; __b4dv
try{ C<_\{de|9
oSavedFile.write(b,nStart,nLen); xT 06*wQ
n = nLen; &pY'
} Movm1*&=
catch(IOException e) P%:?"t+J`;
{ t{c:<nN
e.printStackTrace (); *+*W# de.
} ND1hZ3(^
x\'3UKQP+^
RNc:qV<H
return n; X{x(p
} ;h1hz^Wq
Tz)Ku
|mKohV qr
} LF7 }gQs ^
l :{q I#Q
:m`D
/* t*= nI $
**SiteInfoBean.java >c_fUX={
*/ oJD]h/fQs
package NetFox; {_b2!!p
E0I/]0
]r#b:W\
public class SiteInfoBean { D9TjjA|zS
Ja~8ZrcY
;=n}61
private String sSiteURL; //Site's URL ho$}#o
private String sFilePath; //Saved File's Path HWV A5E[`Y
private String sFileName; //Saved File's Name ogIu\kiZ
private int nSplitter; //Count of Splited Downloading File s=:)!M.i
6hj[/O)E
Y-bTKSn
public SiteInfoBean() +ZbNSN=
{//nSplitter的缺省值为5 VLV]e_D6s
//default value of nSplitter is 5 y7/4u-_c
this("","","",5); ?;o0~][!
} 4L,wBce;,t
- BWf.
)Wle CS_
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R]yce2w"z
{ R ?s;L r
sSiteURL= sURL; D SX%SE)
sFilePath = sPath; }>M\iPO.]*
sFileName = sName; ^1~lnD~0
this.nSplitter = nSpiltter; b_`h2dUq
r^6@Zwox]
?#GTD?3d
} Y:/p0o
=COQv=GT
qv(3qY
public String getSSiteURL() gHc1_G]
{ ;:Z5Ft m
return sSiteURL; iT:i '\~
} iDcTO}
\)5mO 8w
<pV8 +V)
public void setSSiteURL(String value) zgz!"knVx
{ j_d}?jh
sSiteURL = value; p>eYi \'
} R`]@.i4tt
d`TiY`!
d BB?A~
public String getSFilePath() c/ImK`:)4a
{ cz,CL/rno
return sFilePath; mxZ+r#|di
} {96MfhkeBv
:[+8(~| za
!U:&8Le
public void setSFilePath(String value) D} B?~Lls
{ ~ Rk.x +
sFilePath = value; |=ph&9
} @p~scE.#\
x%`YV):*
Wu* 4r0
public String getSFileName() va_u4
{ /ojx$Um
return sFileName; qCI7)L`
} \]4EAKJE
qpFxl
=8#.=J[/
public void setSFileName(String value) ,mx\ -lWFy
{ ;Q,t65+Am
sFileName = value; 0?oL zw&
} p*5_+u
1K#[Ef4
OqS!y( (
public int getNSplitter() im9w|P5
{ Eoixw8hz
return nSplitter; f.$[?Fi
} d:|x e:
C{$iuus0
PX/Y?DP
public void setNSplitter(int nCount) 1OExa<Zq
{ g_{N^wS
nSplitter = nCount; 6)0.q|Q
} ;v\s7y
} n%29WF6Zf
)V~=B]
s}". po]
/* fZ &
**Utility.java x#3*C|A
*/ u; KM[FmK
package NetFox; LDEc}XXb
~b*]jZwT
,ja!OZ0$
public class Utility { RtR@wZ2\s
o}G`t Bz
niCK(&z
public Utility() 2DPv7\fW
{ RHBQgD$
&-qQF`7
m W>Iib|
} >v, si].
pl3ap(/
//线程睡眠 Lu6g`O:['
public static void sleep(int nSecond) ?e6>dNw
{ wdP(MkaV
try{ E"VFBKB
Thread.sleep(nSecond); xE;O =mI
} b MD|
catch(Exception e) g(tVghHxt$
{ M1WD^?tKQ.
e.printStackTrace (); z]rr Q=dAA
} m-azd~r[
} ]w>o=<?b
]i(/T$?~
//日志 4@{?4k-cq
public static void log(String sMsg) _b%)
{ W;=Ae~
System.err.println(sMsg); /;(ji?wN
} Ur]$@N
#0T/^ #
FHU6o910
public static void log(int sMsg) L~t< 0\r
{ 6Jq[]l"v
System.err.println(sMsg); ,k~' S~w.
} 1UJrPM%
} V6P-?Nd
p&RC#wYu
04dz?`HuB
/* p,8~)ic_
**TestMethod.java >nSt<e
*/ }~+,x#
package NetFox; 131(0nl)=I
xrvM}Il
1Zn8CmE V
public class TestMethod { R`c[?U
DNq(\@x[!
s*la`(x
public TestMethod() l[:Aq&[o3
{ ///xx/weblogic60b2_win.exe >-N(o2j3
try{ M{5AQzvs
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); RVV`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); i:aW .QZ.
SiteFileFetch fileFetch = new SiteFileFetch(bean); ="YGR:
fileFetch.start(); B }%2FUv
} ~C%I'z'
catch(Exception e){e.printStackTrace ();} nI]EfHU
<7Pp98si,u
\fTQNF
} !\4B.
#}y8hzS$
?Q-Tyf$3
public static void main(String[] args) 9r]|P}yuS
{ B ktRA
new TestMethod(); SdYf^@%}F
} =${.*,o
} Qh&Qsyo%
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