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)); !uQPc
} a5a($D
for(int i=0;i<nEndPos.length-1;i++) Reatdh
{ S[WG$
nEndPos = nStartPos[i+1]; Sb~MQ_
} #>Zzf
nEndPos[nEndPos.length-1] = nFileLength; lz1wO5%h
} ?-^~f
} sc,Xw:YO
}.s~T#v
/0Ax*919j
//启动子线程 jH_JmYd
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~NW32 O)/
for(int i=0;i<nStartPos.length;i++) GnvL'ESa@M
{ !.d@L6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9k{PBAP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2RSt)3!},
nStartPos,nEndPos,i); ;G%R<Z
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yn#X;ja-
fileSplitterFetch.start(); lok=
} \L"kV!>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )ZN|t?|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); qvPtyc^fN
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", j_Yp>=+[
nEndPos = " + nFileLength); I_RsYw
// fileSplitterFetch[nPos.length-1].start(); fkac_X$7
o}ZdTf=
YpqrZWvh
//等待子线程结束 =ZqT3_
//int count = 0; G;YrF)\
//是否结束while循环 r?/'!!4
boolean breakWhile = false; Fi0GknQ+
EAM5{Nc
I'LnI*
while(!bStop) RsYU59_Y
{ t<#h$}=:Vt
write_nPos(); b9!FC$^J
Utility.sleep(500); WYr/oRO
breakWhile = true; BqT y~{)+
*c2YRbU(
lv04g} W
for(int i=0;i<nStartPos.length;i++) soQ1X@"0
{ >rf'-X4n
if(!fileSplitterFetch.bDownOver) |j,"Pl}il^
{ =uS9JU^E
breakWhile = false; ;n 7/O5M|
break; >Z5gSs0
} :\|SQKD
} 9E6_]8rl
if(breakWhile) `E>1>'
break; Ig f&l`\
"yS _s
P}4QQw
//count++; .4E&/w+
//if(count>4) @<elq'2
// siteStop(); `7r@a
} maNl^i
3qf Ym}d
r[*Vqcz
System.err.println("文件下载结束！"); <_-hRbS
} ~Yy>zUH^X
catch(Exception e){e.printStackTrace ();} X"fb;sGT
} 5;YMqUkw
Ck)*&
H*r)Z90
//获得文件长度 4GX-ma,
public long getFileSize() B\o Mn
{ C)`Fv=]R
int nFileLength = -1; 85LAYaw
try{ z62;cv
URL url = new URL(siteInfoBean.getSSiteURL()); j3{D^|0bP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yjF1}SQ
httpConnection.setRequestProperty("User-Agent","NetFox"); 7Mg=b%IYs
$adbCY\
6V7B;tB
int responseCode=httpConnection.getResponseCode(); %yv<y+yP~
if(responseCode>=400) ]d! UJ&<?
{ qm"rY\:
processErrorCode(responseCode); Q|#W#LV,K
return -2; //-2 represent access is error q!|*oUW
} 1ng!G 7g
?j"KV_
?B2] -+Y
String sHeader; Gz,i~XX
{?:X8&Sf
Hl{S]]z
for(int i=1;;i++) gaZu;t2u
{ -;^j:L{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )-a'{W/t
//Utility.log(in.readLine()); &E.^jR~*
sHeader=httpConnection.getHeaderFieldKey(i); n(;|q&3
if(sHeader!=null) tFp Ygff<
{ s~5[![1 K
if(sHeader.equals("Content-Length")) x-^`~p
{ z=q3Zo
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); iO|se:LY<
break; iOW#>66d
} Ab{ K<:l
} W04@!_) <
else 2AT5
break; H|3:6x
} Uq^#riq
} zh8nc%X{
catch(IOException e){e.printStackTrace ();} Vex{.Vh,"
catch(Exception e){e.printStackTrace ();} Cv6'`",Yzm
;DFSzbF`
21K>`d\
Utility.log(nFileLength); )48QBz?
Rh_np
H4:`6 PSL
return nFileLength; |}=acc/
} _Xk.p_uh
-?V-*jI
5Co
//保存下载信息（文件指针位置） F8jd'OR
private void write_nPos() f4 P8Oz
{ I|gB@|_~
try{ &$`P,i 1)
output = new DataOutputStream(new FileOutputStream(tmpFile)); F\KjEl0
output.writeInt(nStartPos.length); bDL,S?@
for(int i=0;i<nStartPos.length;i++) |H;F7Y_
{ Qz5sxi
// output.writeLong(nPos); 6-$jkto
output.writeLong(fileSplitterFetch.nStartPos); pwL;A3$|
output.writeLong(fileSplitterFetch.nEndPos); < $J>9k
} 49GkPy#]L=
output.close(); .F
} "{@A5A
catch(IOException e){e.printStackTrace ();} 9K{%vK
catch(Exception e){e.printStackTrace ();} le/,R@]B9
} ,(qRc(Ho
9g'LkP
?XrQ53
//读取保存的下载信息（文件指针位置） ;oW6 NJ
private void read_nPos() mF*2#]%dx
{ 0D\#Pq v
try{ [ 9 {*94M
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); I,>-tGK
int nCount = input.readInt(); e:fy#,HEj{
nStartPos = new long[nCount]; xS4w5i2
nEndPos = new long[nCount]; 8m2Tk\;:
for(int i=0;i<nStartPos.length;i++) *|%@6I(
{ =,spvy'"*C
nStartPos = input.readLong(); yu!h<nfzA
nEndPos = input.readLong(); Ugu[|,
} l{I6&^!KS
input.close(); ($au:'kU
} x$5) ^ud?
catch(IOException e){e.printStackTrace ();} UO0{):w>
catch(Exception e){e.printStackTrace ();} iU$] {c2;A
} {.?ZHy\Rk
*H"B _3<n
4>F'oqFF
private void processErrorCode(int nErrorCode) .7e2YI,S
{ ~$Tkn_w#
System.err.println("Error Code : " + nErrorCode); <"{qk2LS1
} Uzz'.K(Mv|
rI= v
S%bCyK%p
//停止文件下载 & ?h#Z!
public void siteStop() s.bc>E0
{ 27 ]':A4_
bStop = true; 1O/+8yw
for(int i=0;i<nStartPos.length;i++) _4"mAPt
fileSplitterFetch.splitterStop(); }Lc-7[/
nzd2zY>V
Wk~WOzr}^
} 0h#lJS*
} UK595n;P
//负责部分文件的抓取 _"?.!
**FileSplitterFetch.java %<k2#6K
*/ Gw>^[dmt!
package NetFox; FQu8vwV6>
cii_U=
lD)%s!
import java.io.*; #pP[xE"Y
import java.net.*; R)_%i<nq\
fol,xMc&
tNO-e|~'
public class FileSplitterFetch extends Thread { HJLu'KY}
M2PAy! J
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String sURL; //File URL CJ1 7n
long nStartPos; //File Snippet Start Position fsJ9bQm/
long nEndPos; //File Snippet End Position U{7w#>V .
int nThreadID; //Thread's ID ~HTmO;HNf"
boolean bDownOver = false; //Downing is over xf<at->
boolean bStop = false; //Stop identical mw_~*Nc'9
FileAccessI fileAccessI = null; //File Access interface 5's87Z;6
XC4X-j3
9>l*lCA
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Ov5"
{ w`4=_J=GO
this.sURL = sURL; 7E!IF>`
this.nStartPos = nStart; >6NRi/[
this.nEndPos = nEnd; rf $QxJ
nThreadID = id; o)Iff)m$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $;1#To
} 3,p]/Z_
+MR.>"
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public void run() *,e:]!*
{ ]JCvyz H
while(nStartPos < nEndPos && !bStop) zz+$=(T:M
{ XG}C+;4Aw
_wTOmz%|R
sx7eC
try{ *^g:P^4
URL url = new URL(sURL); C`$n[kCJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H\h3TdL
httpConnection.setRequestProperty("User-Agent","NetFox"); 7op`s5i
String sProperty = "bytes="+nStartPos+"-"; / : L?~
httpConnection.setRequestProperty("RANGE",sProperty); wP6Fl L
Utility.log(sProperty); F20E_2;@@
1Yq?X:
{9?JjA
InputStream input = httpConnection.getInputStream(); LgKaPg$
//logResponseHead(httpConnection); @OV|]u
f-bVKHt
/35R u}c
byte[] b = new byte[1024]; JW{rA6?
int nRead; gbI^2=YT'
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) B|R@5mjm
{ s"0Y3x3
nStartPos += fileAccessI.write(b,0,nRead); qlb- jL
//if(nThreadID == 1) [h^2Y&Au5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |%J{RA
} j"}*T
|bq$xp
K@sV\"U(*E
Utility.log("Thread " + nThreadID + " is over!"); 'm4W}F
bDownOver = true; ! ='rc-E
//nPos = fileAccessI.write (b,0,nRead); u -;_y='m
} xfpa]Z
catch(Exception e){e.printStackTrace ();} U@HK+C"M|
} MXw hxk#E
} A;*d}Xe&J
8kU!8^mH
<}E!w_yi
//打印回应的头信息 %5eY'
public void logResponseHead(HttpURLConnection con) +_; l|uhT;
{ ;LG#.~f
for(int i=1;;i++) P* w9,
{ e8pG"`wM8
String header=con.getHeaderFieldKey(i); |2RC#]/-Y
if(header!=null) :[O 8
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]~aF2LJ_q
Utility.log(header+" : "+con.getHeaderField(header)); _I)U%?V+
else \9cG36
break; V8rx#H~
} 5_- (<B
} W+PJZn
N>XS=2tzN
7s/u(~d)
public void splitterStop() 2nSSFx r
{ G&i!Hs
bStop = true; mS^tX i5hg
} Ov-icDMm
0s/w,?
PcA2/!a
} |G?htZF
F<qz[,]|-j
@6wFst\t
/* |y0(Q V
**FileAccess.java N'^&\@)xiU
*//文件访问(定位，写) K_RjX>q%N
package NetFox; X~lVVBO
import java.io.*; ^>jwh
NWMFtT
v6>_ j L
public class FileAccessI implements Serializable{ v2B0q4*BS?
~:Ll&29i
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +y&Tf#.V/A
RandomAccessFile oSavedFile; sg$rzT-S4
long nPos; ^Wt*
VU&7P/\f%
n/+.s(7c
public FileAccessI() throws IOException mj9 <%P
{ +VO-oFE|
this("",0); \l9qt5rS
} Dey<OE&
G+X Sfr
n=y[CKS
public FileAccessI(String sName,long nPos) throws IOException 5@+,Xh,H|t
{ dwDcR,z?a
oSavedFile = new RandomAccessFile(sName,"rw"); L)@?e?9
this.nPos = nPos; M<kj_.
oSavedFile.seek(nPos); BT}!W`
} >pp5;h8!
C~o7X^[R\
j)<IRD^
public synchronized int write(byte[] b,int nStart,int nLen) >zXsNeGQR
{ &6ZD136
int n = -1; e[&L9U6GW-
try{ f;W|\z'
oSavedFile.write(b,nStart,nLen); 7?GIS '
n = nLen; 8B\2Zfe
} ^(f"v e#7v
catch(IOException e) TFkZpe;
{ /5Oa,NS7
e.printStackTrace (); va}Pj#=
} {q`jDDM
e=B|==E10M
{L/tst#C
return n; <vONmE a
} }bdmomV
CGY]r.O*
i{`FmrPO~
} o<COm9)i
\s=t|Wpu2
H!5\v"]WB
/* W4pL ,(S
**SiteInfoBean.java .Le?T&_
*/ /OLFcxEWh
package NetFox; ca7=V/i_a{
MvK !u
F'4w;-ax
public class SiteInfoBean { WvBc#s-
$~VRza 8Q
Y2n!>[[.
private String sSiteURL; //Site's URL {`LU+
private String sFilePath; //Saved File's Path 6p?,(
private String sFileName; //Saved File's Name d1AioQ9
private int nSplitter; //Count of Splited Downloading File 8Kg n"M3
V^3L3|k
pEBM3r!X
public SiteInfoBean() eg(6^:z?f
{//nSplitter的缺省值为5 Y9uC&/_C
//default value of nSplitter is 5 p"n$!ilbm
this("","","",5); g!lWu[d
} H`1{_
jcuB
uE%r/:!k4$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) v!<gY m&
{ Sdt`i
sSiteURL= sURL; w80oXXs[#
sFilePath = sPath; piPR=B+
sFileName = sName; [x+FcXb
this.nSplitter = nSpiltter; gp>3I!bo[K
;<&*rnH
AK'[c+2[
} }&cu/o4
N5Q[nd
h"X;3b^ m
public String getSSiteURL() ,]9P{k]O
{ lAb*fafQy
return sSiteURL; KN<S}3MN
} "iy
`uOT+B%R
d,+Hd2o^X
public void setSSiteURL(String value) ]^h]t~
{ ,:%CB"J
sSiteURL = value; U{2BVqM
} /rWd=~[MO
pMw*9sX
^q{9
public String getSFilePath() GeyvId03H
{ C _'%NlJ'
return sFilePath; ~IYUuWF(
} nV"~-On
((H^2KJn
kZR8a(4D
public void setSFilePath(String value) 8EW_V$>R
{ a=J^
sFilePath = value; :flx6,7D
} !hJ+Lp_
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YWe{juXSw
public String getSFileName() Vc 1\i
{ -.1y(k^4E
return sFileName; XW[j!`nlk
} 95ZyP!
sd*p/Q|4
w mn+
public void setSFileName(String value) eWCb73
{ *:Y%HAy*
sFileName = value; V3&RJ k=b
} f86XkECZ;`
6Y^23W F
Y\D!/T
public int getNSplitter() ASKf'\,dV
{ 8m-U){r!U^
return nSplitter; caIL&G,
} /NLui@|R
{+][5<q
52%2R]G!
public void setNSplitter(int nCount) h?AS{`.1
{ =i$Fl{vH
nSplitter = nCount; |t^E~HLm,
} E%yNa]\P
} fa-IhB1!K
r/YMLQ
rA3$3GLQ-
/* I5`4Al
**Utility.java 8NxM4$nQX
*/ -z-C*%~
package NetFox; |LRedD7n
u8'Zl8g
|nc@"OJ
public class Utility { 69PE9zz
xu>9(,l
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public Utility() ]%hn`ZJ
{ zpzK>DH(
,g%0`SO
a+[RS]le
} PxTwPl
)fFb_U
//线程睡眠 q]\:P.x!>
public static void sleep(int nSecond) srPWE^&
{ Za/-i"U
try{ f~t:L,\,
Thread.sleep(nSecond); ~d o9;8v
} HD@$t)mn
catch(Exception e) 3]OE}[R
{ qaqBOHI6G
e.printStackTrace (); m.JBOq=
} ^T( .k=
} ",p;Sd
dWM'fg
//日志 5/q}`T9i%7
public static void log(String sMsg) _- [''(E
{ ko5@qNq
System.err.println(sMsg); ;PF`Wj
} wa(8Hl|Y
9 3U_tQ&1?
P!~MZ+7#&
public static void log(int sMsg) 5 z~1Dw
{ ?# Mr
System.err.println(sMsg); @d^Grm8E
} 4qN{n#{+]
} 4]rnY~
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`0rd26Qro
/* yTyj'-4
**TestMethod.java rJd,Rdt.
*/ zuP B6W^
package NetFox; *zNYZ#
:KH g&ZX7
Y4%:7mw~=
public class TestMethod { v.\*./-i
Dw|}9;5:A
[]x#iOnC&
public TestMethod() rI{=WPI&WU
{ ///xx/weblogic60b2_win.exe z_g~
try{ )W|w C#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "-y-iJ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); UT>s5C
SiteFileFetch fileFetch = new SiteFileFetch(bean); zFfoqb#*g
fileFetch.start(); (As#^q\>B
} 1h(0IjG8
catch(Exception e){e.printStackTrace ();} mCRt8rY;
-HQQw$
| H!28h
} tv>>l%
|].pDwgt
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public static void main(String[] args) ADZ};:]
{ 0,r}o
new TestMethod(); IOTR/anu
} Kfm5i Q
} z+ s6)Ad
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