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)); 4EFP*7X
} yb-/_{Y
for(int i=0;i<nEndPos.length-1;i++) 8O.5ML{
{ (RLJ_M|;/b
nEndPos = nStartPos[i+1]; ?j$*a7[w
} 9=G dj!L
nEndPos[nEndPos.length-1] = nFileLength; `$>cQwB,D
} 7VA6J-T
} S^ JUQx7
u`wT_?%w
ixJwv\6Y
//启动子线程 D,SL_*r{
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6gD|QC~;
for(int i=0;i<nStartPos.length;i++) 6'JP%~QlS
{ B:tGD@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B=hJ*;:p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), fZt3cE\
nStartPos,nEndPos,i); YL@d+ -\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]]_H|tO
fileSplitterFetch.start(); * TR~>|
} !' jXN82
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -1 _7z{.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >Av%[G5=h#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", W'<cAg?
nEndPos = " + nFileLength); x^JjoI2vf
// fileSplitterFetch[nPos.length-1].start(); fa;GM7<e)
U4,hEnJBT
eZ +uW0
//等待子线程结束 OvW/{
//int count = 0; k<\]={|=
//是否结束while循环 Nx"v|"
boolean breakWhile = false; AZadNuL/
e,Fe,5E&g
1Qgd^o:d
while(!bStop) >zWVM1\\j
{ &)|3OJ'o
write_nPos(); js8\"
Utility.sleep(500); N0G-/
breakWhile = true; #L,5;R{`
\^%5!
O5p]E7/e
for(int i=0;i<nStartPos.length;i++) JPTVZ
{ @X6|[r&Z
if(!fileSplitterFetch.bDownOver) u(|k/~\
{ Ig6>+Mw
breakWhile = false; iXDQ2&gE*
break; xj!_]XJ^w
} T4{&@b 0*
} v]HiG_C
if(breakWhile) ^6 sT$set
break; o$r]Z1
ywV8s|o
U"v}br-kb
//count++; /< CjBW:
//if(count>4) IK-E{,iKc
// siteStop(); k&P_ c
} ')w*c
V F'! OPN
:1wMGk
System.err.println("文件下载结束！"); Xsc5@O!
} YA>du=6y\
catch(Exception e){e.printStackTrace ();} ]-aeoa#
} (UV+/[,
8EPV\M1%
=7mR#3yt
//获得文件长度 +mT}};-TS
public long getFileSize() G K @]61b
{ 3EcmNwr
int nFileLength = -1; 5Ffz^;i
try{ q'?:{k$%
URL url = new URL(siteInfoBean.getSSiteURL()); gH0B[w ]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j]<T\O>t>
httpConnection.setRequestProperty("User-Agent","NetFox"); _rqOzE)
`B6{y9J6
K`FgU7g{
int responseCode=httpConnection.getResponseCode(); *[7,@S/<F
if(responseCode>=400) bhSpSul
{ O`dob&C
processErrorCode(responseCode); = sIR[V'(
return -2; //-2 represent access is error 685o1c|
} @X/S h:
<' %g $"
<E BgHD)
String sHeader; IO xj$?%l
ZZE
%`}CbD6
for(int i=1;;i++) .KT+,Y
{ 1qUdj[Bj
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); VJCh5t*
//Utility.log(in.readLine()); S53%*7K.
sHeader=httpConnection.getHeaderFieldKey(i); n/8Kb.Vf
if(sHeader!=null) 9rao&\eH
{ #G.3a]p}"
if(sHeader.equals("Content-Length")) #K!Df%,<
{ cJ8F#t
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2c%}p0<;|?
break; !icpfxOpjQ
} kFM'?L&
} sp**Sg)
else 4&ea*w
break; sD{b0mZT
} ;6b#I$-J-
} \ @N>38M
catch(IOException e){e.printStackTrace ();} i8B%|[nm
catch(Exception e){e.printStackTrace ();} <YeF?$S}
_;B!6cRLps
7Xad2wXn
Utility.log(nFileLength); kw-/h+lG
FOk @W&
U*&ZQw
return nFileLength; Km <Wh=
} ^2kWD8c*
"ZyHt HAK
3yKI2en"
//保存下载信息（文件指针位置） +cV!=gDT
private void write_nPos() |Lhz^5/
{ <,E*,&0W
try{ pz&=5F
output = new DataOutputStream(new FileOutputStream(tmpFile)); hx^a&"
output.writeInt(nStartPos.length); 'o7PIhD"
for(int i=0;i<nStartPos.length;i++) $k`8Zx w
{ %C3cdy_c
// output.writeLong(nPos); Q"Ec7C5eM
output.writeLong(fileSplitterFetch.nStartPos); *c AoE l
output.writeLong(fileSplitterFetch.nEndPos); sRZ:9de+
} 5dgBSL$A}]
output.close(); R&4E7wrdP
} AltE~D/4
catch(IOException e){e.printStackTrace ();} wFJK!9KA8
catch(Exception e){e.printStackTrace ();} fjWh}w8
} 8zc!g|5"
Y=rr6/k
llleo8
//读取保存的下载信息（文件指针位置） z;/'OJ[.
private void read_nPos() *n*y!z
{ U2AGH2emw
try{ 2T3DV])Q
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /J+)P<_A
int nCount = input.readInt(); AfEEYP)N
nStartPos = new long[nCount]; &!a2%%1#N
nEndPos = new long[nCount]; q],R6GcVr
for(int i=0;i<nStartPos.length;i++) |f:d72{Qr
{ btF%}<o)
nStartPos = input.readLong(); [;=ky<K0E
nEndPos = input.readLong(); Dgm%Ng
} A C^[3
input.close(); cP2R24th
} ^<VE5OM
catch(IOException e){e.printStackTrace ();} -{*V)J_Co
catch(Exception e){e.printStackTrace ();} Uu X"AFy~\
} 668bJ.M\O
1QJ$yr
I.u,f:Fl'
private void processErrorCode(int nErrorCode) N1!5J(V4
{ 9-Qtj49
System.err.println("Error Code : " + nErrorCode); ]'h)7
} J3x7i8
lDU:EJ&DHE
~|9LWp_
//停止文件下载 SU'1#$69F
public void siteStop() .:ZXtU
{ 62x< rph
bStop = true; (A'q@-XQ
for(int i=0;i<nStartPos.length;i++) 02^(z6K'&?
fileSplitterFetch.splitterStop(); H27Oq8
#=H}6!18
)Zf}V0!?+
} gyQ9Z}
} d95N$n
//负责部分文件的抓取 jN}7BbX
**FileSplitterFetch.java wmr%h q
*/ thPH_DW>eb
package NetFox; ]XGn2U\
*6D%mrK
g**%J Xo
import java.io.*; 9H}iX0O
import java.net.*; `O=;E`ep
!en F8a
O4PdN?
public class FileSplitterFetch extends Thread { :/[YY?pg-
,L{o,qzC
06@0r
String sURL; //File URL Wx|6A#cg!
long nStartPos; //File Snippet Start Position sR>;h /
long nEndPos; //File Snippet End Position .(dmuV9
int nThreadID; //Thread's ID T{H#]BF<E
boolean bDownOver = false; //Downing is over (bFWT_CChz
boolean bStop = false; //Stop identical HA.NZkq.tV
FileAccessI fileAccessI = null; //File Access interface _{`'{u
d)GkXll1D
mz VuQ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5-5(`OZ{'
{ 3Ra\2(bR
this.sURL = sURL; 7YXXkdgbd
this.nStartPos = nStart; ({_:^$E\
this.nEndPos = nEnd; S7NnC4)=-f
nThreadID = id; Bx}0E
fileAccessI = new FileAccessI(sName,nStartPos);//定位 h>^jq{yu
} mf]( 3ZL
4}8+)Pd
N]s7/s
public void run() p]V-<
{ `\|3 ~_v
while(nStartPos < nEndPos && !bStop) [rUh;_b\D
{ qtwT#z;Y
2.Eu+*UC
28Ssb|
try{ QK3j_'F=E
URL url = new URL(sURL); Q 9gFTLQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %$Jqt
httpConnection.setRequestProperty("User-Agent","NetFox"); =wlm
String sProperty = "bytes="+nStartPos+"-"; CVGOX z
httpConnection.setRequestProperty("RANGE",sProperty); -M1~iOb
Utility.log(sProperty); Xc9p;B>^Ts
(w#slTFT
pRiH,:\
InputStream input = httpConnection.getInputStream(); 4gv.E 0Fo
//logResponseHead(httpConnection); _8x'GK tU
KT lP:pB;
*_{l
byte[] b = new byte[1024]; p'Y&Z?8
int nRead; {7K'<ti
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ET,0ux9F
{ N o_$!)J.
nStartPos += fileAccessI.write(b,0,nRead); ;o_V!<$
//if(nThreadID == 1) n{.*El>{
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Msv*}^>
} <uBhi4
k%Ma4_Z
R8=I)I-8
Utility.log("Thread " + nThreadID + " is over!"); oeu|/\+HW
bDownOver = true; 3WO#^}t
//nPos = fileAccessI.write (b,0,nRead); j[m_qohd7
} (c(-E|u.
catch(Exception e){e.printStackTrace ();} g+>=C
} D0Vyh"ua
} -~vl+L
dN]Zs9]
.])>A')r
//打印回应的头信息 H )BOSZD
public void logResponseHead(HttpURLConnection con) Sc;iAi (
{ 1a($8>
for(int i=1;;i++) )K>Eniou
{ sorSyuGr
String header=con.getHeaderFieldKey(i); dN$ 1$B^k
if(header!=null) w+Z--@\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); a,/M'^YyN
Utility.log(header+" : "+con.getHeaderField(header)); #dva0%-1
else _o@(wGeu#
break; _'!aj+{
} D~G5]M,}$
} ,s1&O`
-M7K8
pP|,7c5
public void splitterStop() U0NOU#
{ ,vY)n6
bStop = true; g\ErJ+i
} ! (2-(LgA
|ZvNH ~!
<Vz<{W3t
} [<]Y+33
rPRrx-A
BQyvj\uJ
/* jrIA]K6
**FileAccess.java =?=)s
*//文件访问(定位，写) 5;X {.2
package NetFox; El~-M`Gf
import java.io.*; BX@pt;$ek7
uz]E_&2
1a<]$tZk
public class FileAccessI implements Serializable{ k1wCa^*gc
*f79=x
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ?QGmoQ)
RandomAccessFile oSavedFile; ~}h^38
long nPos; q.-y)C) ;
?3`q+[:
92!JKZe
public FileAccessI() throws IOException *Wzwbwg
{ %PzQ\c
this("",0); yc*<:(p
} 0eFb?Z0]
{]=v]O|,
I[ai:
public FileAccessI(String sName,long nPos) throws IOException Am=wEu[b
{ K>kLUcC7Z
oSavedFile = new RandomAccessFile(sName,"rw"); vK(I3db!
this.nPos = nPos; 2A*/C7
oSavedFile.seek(nPos); tG/1pW
} -PM)EGSk{
M:_!w[NiLp
K'NcTw#f
public synchronized int write(byte[] b,int nStart,int nLen) \EZ+#3u
{ S."7+g7Ar
int n = -1; Kh)FyV
try{ /KAlK5<
oSavedFile.write(b,nStart,nLen); Q!K`e)R
n = nLen; ^|aNG`|O
} @&5A&(
catch(IOException e) \83sSw
{ ;W0]66&
e.printStackTrace (); +e'X;
} GQx9u^>
>dk9f}7-
]NtSu%u
return n; \X& C4#
} g]|_ `
IZ8y}2
?>V6P_r>
} |) Pi6Y
y? "@v.
!9r:&n.\
/* 4\p-TPM
**SiteInfoBean.java 2J<&rKCF
*/ 9cQ_mgch
package NetFox; cx^{/U?9}
5lTD]d
A62<]R)n
public class SiteInfoBean { ]TSg!H
-#?<05/C>
dn,gZ"<
private String sSiteURL; //Site's URL EA|k5W*b
private String sFilePath; //Saved File's Path |)o#|Qo
private String sFileName; //Saved File's Name v7IzDz6gF
private int nSplitter; //Count of Splited Downloading File t)N;'v &
DA"}A`HfI
zX kx7d8
public SiteInfoBean() +y&d;0!
{//nSplitter的缺省值为5 H9` f0(H
//default value of nSplitter is 5 6:?rlh
this("","","",5); }"zC >eX&
} \M(*=5
7zDiHac
+a|/l
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) '#Dg8/r!
{ ALGgAX3t
sSiteURL= sURL; lj2=._@R
sFilePath = sPath; },c,30V'
sFileName = sName; a<m-V&4x
this.nSplitter = nSpiltter; [pgZbOIN37
zgKY4R{V
~rv})4h
} GXX+}=b7qO
&~-~5B|3"
5j^NV&/_
public String getSSiteURL() E\{<;S
{ 8Fq_i-u
return sSiteURL; .L;@=Yg)
} N[U9d}Zv
mlu 3K
Zk? =
public void setSSiteURL(String value) i0pU!`0
{ *'ZN:5%H
sSiteURL = value; uDayBaR
} 0ys~2Y!eH
xxa} YIe8
\#dl6:"
public String getSFilePath() 5bX6#5uP1
{ Lz4ehWntO
return sFilePath; ?o[L7JI
} >SCGK_Cr2
9=+-QdX+0]
.~klG&>aV
public void setSFilePath(String value) 6)*xU|fU
{ >HTbegi
sFilePath = value; \4bWWy
} `M@Ak2gcR+
|)U|:F/{@
3|kgTB-
public String getSFileName() g+[kde;(^
{ O`W%Tr
return sFileName; H\G{3.T.9
} IazkdJX~
i~yX tya
,Og4 ?fS
public void setSFileName(String value) >PalH24]
{ {aj/HFLNY
sFileName = value; d;G~hVu
} i|$z'HK;+
aXR%;]<Dw
ffcLuXa
public int getNSplitter() f_6`tq m%
{ Q/^A #l[
return nSplitter; XGs^rIf
} TZB+lj1
Dy9\O77>
?y7w}W
public void setNSplitter(int nCount) 2qj{n+
{ -|_ir-j
nSplitter = nCount; f~M8A.
} >|udWd^$3
} ?&c:q3_-Z
:pC;`iQ
8L{u}|{
/* ;+_8&wbqW
**Utility.java G*n2Ii
*/ \L]|-f(4
package NetFox; hKe30#:v
=,/D/v$m'2
zICI_*~
public class Utility { v%91k
XB\zkf_}Xc
BGWAh2w6
public Utility() }KB[B
{ *y7 $xa4
trYTs,KV
M<`|CVl
} >- Bg%J9
"QY1.:o<(
//线程睡眠 B;t=B_oK
public static void sleep(int nSecond) N}Vn;29
{ ;A#~`P
try{ *|RS*ABte
Thread.sleep(nSecond); &O1v,$}'
} GESXc$E8
catch(Exception e) 0|Ucd
{ (JZ".En#X
e.printStackTrace (); !]b@RUU
} `a4 $lyZ
} %_f;G+fK\p
ef]B9J~h
//日志 ZF{~ih*^u
public static void log(String sMsg) m_lrPY-
{ uP|FJLY
System.err.println(sMsg); ]0~qi@
} b|?;h21rG
dHII.=lT
Spj9H?m
public static void log(int sMsg) P_Uutn~
{ ($d4:Ww
System.err.println(sMsg); N}QFGX
} 5h^[^*A?
} km 5E)_]
`,#!C`E 9
'2v f|CX
/* m,6hee
**TestMethod.java ^.HWkS`e
*/ <GZhH:
package NetFox; +R\~3uj[7
,2zKQ2z
|uUuFm
public class TestMethod { !$>G#+y
_s>^?x}
JvJ;bFXD
public TestMethod() zSgjp\
{ ///xx/weblogic60b2_win.exe p_6P`Yx^e
try{ W~dE
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8/q*o>[?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -!R l(if
SiteFileFetch fileFetch = new SiteFileFetch(bean); l,y^HTc}7/
fileFetch.start(); aN'0}<s
} 'NjSu64W
catch(Exception e){e.printStackTrace ();} Vy;_GfT$
!5.v'K'
PqfVX8/q0
} </ZHa:=7
l1RlYl5
}td6fj_{
public static void main(String[] args) k?-S`o%Q
{ CWMlZVG
new TestMethod(); UK:M:9
} 9::YR;NY
} uI9lK
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