http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); +s(IQt
} Q'Kik5I
for(int i=0;i<nEndPos.length-1;i++) BOiz ~h6
{ s!;VUr\
nEndPos = nStartPos[i+1]; L8w76|
} r|\'9"@
nEndPos[nEndPos.length-1] = nFileLength; eo*u(@
} A;WwS?fyQ
} [T[9*6Kt
p1VahjRE-
r{B,uj"
//启动子线程 0.BUfuuh
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &kjwIg{
for(int i=0;i<nStartPos.length;i++) &c<}++'h
{ @FdCbPl$
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), JfP\7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <X I35\^
nStartPos,nEndPos,i); 4>"cc@8&~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4lh
fileSplitterFetch.start(); Ux)p%-
} q4.dLU,1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'f?&EsIV?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); tC@zM.v%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", mQ^@ \s
nEndPos = " + nFileLength); o&XMgY~
// fileSplitterFetch[nPos.length-1].start(); OBw`!G*w
_[{:!?-?
VmOFX:j!,
//等待子线程结束 bDFCZH-:'O
//int count = 0; A{8K#@!
//是否结束while循环 0nD=|W\@{
boolean breakWhile = false; DYT -#Ht
aa0`y
iy.%kHC
while(!bStop) @ Zgl>
{ ULNAH`{D
write_nPos(); DNW2;i<hsz
Utility.sleep(500); D _bkUR1
breakWhile = true; +{C9uY)$vf
`J=1&ae{
>\?z37:T
for(int i=0;i<nStartPos.length;i++) ]Ic?:lKN
{ V^`?8P8d
if(!fileSplitterFetch.bDownOver) 4$?wD <
{ zOao&
breakWhile = false; `Ge+(1x
break; ^QXw[th!d
} zOiY0`=
} JwI`"$>w
if(breakWhile) ,na=~.0R:
break; N,/BudFo
D-o7yc"K
b,rH&+2H
//count++; .W@(nQ-<
//if(count>4) $['7vcB^
// siteStop(); E/dO7I`B
} g* \P6
jr[<i\!
|,1bkJt
System.err.println("文件下载结束！"); da00p-U
} }dd k}wga
catch(Exception e){e.printStackTrace ();} sk7rU+<
} W<rTq0~$?
$@_<$t
FM9X}%5nu9
//获得文件长度 ;Y@!:p-H
public long getFileSize() %l8*t$8
{ 4#@W;'
int nFileLength = -1; ib(>vp$V
try{ SvX=isu!.
URL url = new URL(siteInfoBean.getSSiteURL()); C?[a3rNH(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B|Fl,55
httpConnection.setRequestProperty("User-Agent","NetFox"); cZDxsd]
9RCO|J
J+}+"h~.
int responseCode=httpConnection.getResponseCode(); {ywXz|TP
if(responseCode>=400) (@KoqwVWc
{ |%'6f}fnE
processErrorCode(responseCode); "+n4c'
return -2; //-2 represent access is error w\o)bn
} + %MO7vL
(Pk"NEP
pwFU2}I
String sHeader; FpdDIa
]3O 4\o
Wa[x`:cT?u
for(int i=1;;i++) e~+(7_2
{ f=:3!k,S
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); wovmy{K
//Utility.log(in.readLine()); B]^>GH
sHeader=httpConnection.getHeaderFieldKey(i); T|o`a+?
if(sHeader!=null) ?o~:'Z
{ @cuD8<\i
if(sHeader.equals("Content-Length")) Ka]J^w;a
{ $=PWT-GIR
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~!nLbK2
break; kgbobolA
} Y{k>*: Ax_
} W NwJM
else s;fVnaqG:
break; eeW' [
} uFwU-LCe
} )\T@W
catch(IOException e){e.printStackTrace ();} ~Na=+}.q_
catch(Exception e){e.printStackTrace ();} a -xW8
XJx,9trH
$nB-ADRu@
Utility.log(nFileLength); 3[0w+{(Q
Yz&*PPx
QU^/[75Ea0
return nFileLength; <91t`&aWW
} *2JH_Cj`
le7 `uz!%
?xtt7*'D
//保存下载信息（文件指针位置） kAZC"qM%i
private void write_nPos() *:=];1O
{ UGhW0X3k
try{ ,M\j%3
output = new DataOutputStream(new FileOutputStream(tmpFile)); J0^{,eY<
output.writeInt(nStartPos.length); cPpu
for(int i=0;i<nStartPos.length;i++) 5cD XWF
{ s1X]RXX&j
// output.writeLong(nPos); 1s#yWQ
output.writeLong(fileSplitterFetch.nStartPos); n,t6v5>88
output.writeLong(fileSplitterFetch.nEndPos); <,jAk4
} kWB, ;7
output.close(); Ya}T2VX
} cCM j\H@
catch(IOException e){e.printStackTrace ();} UdT&cG
catch(Exception e){e.printStackTrace ();} [RAj3Fr0
} P3'2IzNw
+"]oc{W!
Zxg1M
//读取保存的下载信息（文件指针位置） {5T0RL{\N
private void read_nPos() 9*#$0Y=
{ G1}~.%J
try{ 1#grB(p?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); x!'7yx
int nCount = input.readInt(); hVMYB_<~
nStartPos = new long[nCount]; -#hK|1]
nEndPos = new long[nCount]; Q]< (bD.7
for(int i=0;i<nStartPos.length;i++) 2q)T y9
{ y^2#9\}K
nStartPos = input.readLong(); tf4*R_6;1$
nEndPos = input.readLong(); yZq?B
} LO"_NeuL
input.close(); 's)fO#
} G49Ng|qn
catch(IOException e){e.printStackTrace ();} bfFmTI$,
catch(Exception e){e.printStackTrace ();} 31WZJm^
} |2z}Xm5\
{tPnj_|n<
xN6>2e
private void processErrorCode(int nErrorCode) wD`[5~C{
{ M]c7D`%s
System.err.println("Error Code : " + nErrorCode); YzVN2f!n
} "37*A<+f
QQ@9_[N
:Df)"~/mO+
//停止文件下载 Z;hyi'rPJ
public void siteStop() d-~vR(tU
{ F&xv z2G
bStop = true; /T,zZ9=
for(int i=0;i<nStartPos.length;i++) zVdKYs i^
fileSplitterFetch.splitterStop(); VsEGX@;tO
x8Q~VVZr
l$F_"o?&S@
} l{8CISO*
} SaCx)8ul0
//负责部分文件的抓取 'f 3HKn<L
**FileSplitterFetch.java \I;cZ>{u"}
*/ h-7A9:
package NetFox; 't7Z] G
9qEOgJ
[6H}/_nD
import java.io.*; ]3}feU+
import java.net.*; #zxd;;p3
rsWQHHkO
V{!lk]p}a
public class FileSplitterFetch extends Thread { TZ'aNcGg
5:c;RRn
+kM\ D~D1
String sURL; //File URL {ih:FcI
long nStartPos; //File Snippet Start Position L_^`k4ct
long nEndPos; //File Snippet End Position cv= \g Z
int nThreadID; //Thread's ID EJ G2^DSS
boolean bDownOver = false; //Downing is over /9pbnzn
boolean bStop = false; //Stop identical X<Z(]`i
FileAccessI fileAccessI = null; //File Access interface _ \l HI
K5{{:NR$
QP:9%f>=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Rb#/qkk/
{ pw=F' Y@N
this.sURL = sURL; [<yz)<<
this.nStartPos = nStart; $.a|ae|K
this.nEndPos = nEnd; F99A;M8(
nThreadID = id; g92dw<$>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Hq?&Qo
} vevf[eO-
4f!dYo4L
QWw"K$l
public void run() ;u,rtEMy;
{ _%%yV
while(nStartPos < nEndPos && !bStop) FuuS"G,S
{ %*jGim~s
`gI~|A4
&mcR
try{ "qS!B.rt:
URL url = new URL(sURL); jn^fgH?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Oxv+1Ub<Dv
httpConnection.setRequestProperty("User-Agent","NetFox"); G,]z(%
String sProperty = "bytes="+nStartPos+"-"; bEd?^h
httpConnection.setRequestProperty("RANGE",sProperty); zks#EzQ
Utility.log(sProperty); ;,rnk-
d@ZoV
/ERNS/w
InputStream input = httpConnection.getInputStream(); Zi/-~')E
//logResponseHead(httpConnection); 6 Uw;C84!
NI8~QeGah
9`BEi(z
byte[] b = new byte[1024]; ra]:$XJ5=a
int nRead; zw]3Vg{T
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) q!&B6]
{ .b,~f
nStartPos += fileAccessI.write(b,0,nRead); l<xFnj
//if(nThreadID == 1) +*C^:^jA
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gLD{1-v
} f*<ps o
!!WJn}
c;wA
Utility.log("Thread " + nThreadID + " is over!"); MqdB\OW&
bDownOver = true; -2 xE#r
//nPos = fileAccessI.write (b,0,nRead); &DLhb90
} i=L8=8B`
catch(Exception e){e.printStackTrace ();} 1"O&40l
} 4)^vMG&
} RL*]g*
O:JPJ"!
(B:uc_+
//打印回应的头信息 {2:d`fqD
public void logResponseHead(HttpURLConnection con) (;UP%H>
{ /lJjQ]c;>
for(int i=1;;i++) 59i]
{ PBrnzkoY
String header=con.getHeaderFieldKey(i); %K zbO0
if(header!=null) x> \Bxa8
//responseHeaders.put(header,httpConnection.getHeaderField(header)); &Mj1CvCv
Utility.log(header+" : "+con.getHeaderField(header)); BFh$.+D
else /cfHYvnz
break; Rg&19}BU
} A$@o'Q;he
} :Fw?{0
ZMdW2_*F
fa{@$ppx
public void splitterStop() _CE9B e\
{ M/#U2!iFk
bStop = true; K/|
} TsD;Kl1
v459},!P
Q]#Z9H
} 76u{!\Jo/{
X$V|+lTk
-k{Jp/-D
/* L\L"mc|O
**FileAccess.java 7|Dn+=
*//文件访问(定位，写) }9CrFTbx;
package NetFox; iyj3QLqE
import java.io.*; r6t&E%b
Hf%_}Du /`
QNArZ6UQ
public class FileAccessI implements Serializable{ GV8)Kor%
J=*K"8Qr
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 e$|VG* d
RandomAccessFile oSavedFile; m7m \`;
long nPos; y5u\j{?Te
Uh}X<d/V
J8;Okzb!L
public FileAccessI() throws IOException C:GvP>
{ fsvYU0L
this("",0); w$>3pQ8d
} Rd%0\ B
1[DS'S
A[H;WKn0
public FileAccessI(String sName,long nPos) throws IOException v!trsjb
{ T~J?AKx
oSavedFile = new RandomAccessFile(sName,"rw"); uD(t`W"
this.nPos = nPos; z-@-O
oSavedFile.seek(nPos); LgHJo-+>
} d(S}NH
10MU-h.)
\hbiU]
public synchronized int write(byte[] b,int nStart,int nLen) |ym%| B
{ tcA;#^jc
int n = -1; U3F3((EYJ
try{ ^~l $&~
oSavedFile.write(b,nStart,nLen); f&yQhe6q
n = nLen; =M<z8R
} zZ,Yfd|W
catch(IOException e) Of`c`-<j
{ ]k*1KP
e.printStackTrace (); ,4Y*:JU4
} =.b Y#4
$bGD%9 z
I=[cZ;t
return n; &&PgOFD
} SRCOs1(EK9
%&<W(|U1<
4*M@]J "
} El6bD% \G
g$3>~D
>}SRSqJu
/* JD~aUB%
**SiteInfoBean.java &71e5<(dG
*/ If'2rE7J
package NetFox; n93zD*;5
6[?}6gQ
j}RzXJ~t
public class SiteInfoBean { YKs4{?vw
1V%'.l9
Wsm`YLYkt!
private String sSiteURL; //Site's URL wFL3&*
private String sFilePath; //Saved File's Path 84M3c
private String sFileName; //Saved File's Name CLN+I'uX0
private int nSplitter; //Count of Splited Downloading File %S#WPD'Y
`|<+ ?
(~()RkT
public SiteInfoBean() Vk7=7%xW
{//nSplitter的缺省值为5 <4mQ*6
//default value of nSplitter is 5 g:gB`8w?
this("","","",5); Jps .;yjk
} ;&?pd"^<_Z
A/ 0qk
J_ J+cRwq
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?63&g{vA
{ \##`pa(8
sSiteURL= sURL; +v15[^F
sFilePath = sPath; Q2\
sFileName = sName; [rdsv
this.nSplitter = nSpiltter; G;]:$J
_N'75
)|]Z>>%t
} @2' %o<lF
(ZPXdr
7ZFJexN]
public String getSSiteURL() o4)hxs
{ F~_;o+e;X
return sSiteURL; &KqVN]1+^
} r4;Bu<PQN1
!T'X 'Q
7Dt"]o"+
public void setSSiteURL(String value) z\.1>/Z=
{ nyhMnp#<
sSiteURL = value; RP` `mI
} ?_ RYqolz
ek)Xrp:2
6/2v
public String getSFilePath() JBcY!dy-d
{ \6sQJq
return sFilePath; slvq9,
} 'b[0ci:
)U(u>SV(\
^7u#30,}3~
public void setSFilePath(String value) (5`T+pAsV
{ N z~"vi(t
sFilePath = value; `WlE| G[
} /f3m)pT
#`/QOTnm2c
`Q%NSU?
public String getSFileName() 3jPB#%F
{ >oqZ !V5[
return sFileName; |9,UaA
} t26ij`V
;f%|3-q1[
p&3> `C
public void setSFileName(String value) h<3p8eB
{ P s#>y&
sFileName = value; kO ![X^V
} Y60"M4j
. U/k<v<)6
G5c7:iGm/c
public int getNSplitter() ~_PYNY`"
{ Ew4g'A:H
return nSplitter; x9V {R9_gf
} 5py R~+
KQ)T(mIqp
lbkLyp2
public void setNSplitter(int nCount) #T%zfcUj
{ _413\`%8?
nSplitter = nCount; xzk}[3P{
} w0Ij'=:
} Y@}FL;3
m6U8)!)T
s~$zWx@v
/* =`p&h}h-L
**Utility.java r_2btpL^
*/ Y'N'hRD
package NetFox; {;k_!v{
nW5K[/1D
]Oso#GYD
public class Utility { >saI+u'o
GS%b=kc
_01Px a2.
public Utility() A3s57.Z]|
{ /77z\[CeYH
#x~_`>mDN
2k+16/T
} -e*BqH2t
v2J0u:#,
//线程睡眠 ")M;+<c"l
public static void sleep(int nSecond) ;[Tyt[
{ \ X$)vK
try{ -P#nT 2
Thread.sleep(nSecond); j>!sN`dBj
} Kbas-</Si
catch(Exception e) "DjU:*'
{ `P.CNYR<J
e.printStackTrace (); K^H>~`C=
} Z[} $n-V
} "$8w.C
p>p'.#M
//日志 gpAHC
public static void log(String sMsg) s*JE)
{ 3qo e^e
System.err.println(sMsg); k18$JyaG
} yWHne~!
X47Ol
3w'W~
public static void log(int sMsg) mo9$NGM&}
{ ;0j*>fb\q7
System.err.println(sMsg); k/#>S*Ne
} u(hC^T1
} a8JN19}D
}W}G X(?P
Y/P]5: =h
/* hTTfJDF
**TestMethod.java Hsl{rN
*/ p >aw
package NetFox; 'v`_Ii|-
2U%qCfh6|
Wk[)+\WQ?
public class TestMethod { !K\itOEP-
8c).8RLf
mP!N<K
public TestMethod() ) `I=oB
{ ///xx/weblogic60b2_win.exe an KuTI
try{ fuyl/bx}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); \)R-A '*U
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); e\.HWV]I
SiteFileFetch fileFetch = new SiteFileFetch(bean); };p~A-E=
fileFetch.start(); $ !5f"<FCB
} K:w]>a
catch(Exception e){e.printStackTrace ();} (1 yGg==W.
%#9P?COs&W
.,mM%w,^O
} xjrlc9
A& =pw#
stXda@y<p
public static void main(String[] args) o<J5!
{ [&daG:
new TestMethod(); o2}N=|&
} sR!+d:LJ4
} Tc_do"uU
点击下载更多相关资料