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)); ?z6C8T~+
} ]8^2(^3ct
for(int i=0;i<nEndPos.length-1;i++) fkYQ3d,`
{ OV[-m;h|
nEndPos = nStartPos[i+1]; Zwcb5\Q
} 0K!9MDT}*
nEndPos[nEndPos.length-1] = nFileLength; yP-Dj ,
} >eXNw}_j
} |LQmdgVr$
9.R_=
g (~&
//启动子线程 D"hiEz
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; yF:fxdpw
for(int i=0;i<nStartPos.length;i++) aZ'p:9e
{ xnLfR6B
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OJ 2M_q)e
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), eD}Ga4
nStartPos,nEndPos,i); 4ldN0_T5
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R[Rs2eS_
fileSplitterFetch.start(); ,ToED
} qGw6Wp~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), suVS!} C
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~UnfS};U
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6B 8!2
nEndPos = " + nFileLength); vw3W:TL
// fileSplitterFetch[nPos.length-1].start(); 2|cIu 'U
>[p+L='
ZGrV? @o,6
//等待子线程结束 [`&cA#C9Yp
//int count = 0; >A)he!I
//是否结束while循环 G{J9Fb8
boolean breakWhile = false; %H@fVWe2wT
R =jK3yfw
AkF1Hj
while(!bStop) %8ul}}d9
{ R6!3Y/Q@
write_nPos(); 2@H~nw 0
Utility.sleep(500); bUBuJ
breakWhile = true; ^,X+ n5q;m
HCP Be2
[W;14BD7
for(int i=0;i<nStartPos.length;i++) %!q(zql
{ $lv g.u
if(!fileSplitterFetch.bDownOver) V}(%2W5X+
{ M:x8]TA
breakWhile = false; jJf|Ok:G{
break; DJbj@ 2W[
} |h'ugx1iY
} 6`yq4!&v
if(breakWhile) !=-l760
break; bNC1[GG[
9Hu%Z/[!p
8FMP)N4+
//count++; FrVD~;
//if(count>4) iD\joh-C
// siteStop(); +EFurdX\
} zJ\I%7h*
Fm@GU
LR^b?.#>
System.err.println("文件下载结束！"); IuTTMAt
} T}zi P
catch(Exception e){e.printStackTrace ();} [-%oO
} w90y-^p%
S`-z$ph}
A(C3kISM
//获得文件长度 Q:-/@$&i
public long getFileSize() E/am^ TO`
{ S-1}3T%
int nFileLength = -1; L4dbrPE*0
try{ 5/(Dh![l
URL url = new URL(siteInfoBean.getSSiteURL()); wCdUYgsPT"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ubgq8@;
httpConnection.setRequestProperty("User-Agent","NetFox"); OZ-F+#d
TEYbB=.
gC'GZi^
int responseCode=httpConnection.getResponseCode(); 2n@"|\uHD
if(responseCode>=400) xv)7-jlx
{ !is8`8F8
processErrorCode(responseCode); ZpwB"%e$
return -2; //-2 represent access is error n"Ev25%
} ?6[>HX;
s2tEyR+gW
]\GGC]:\@
String sHeader; ]s u\[?l
\'p)kDf
Wl*\kQ}U
for(int i=1;;i++) rsIjpPa
{ ^RY_j>i
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); U$-FQRM4K
//Utility.log(in.readLine()); lKm?Xu'yH
sHeader=httpConnection.getHeaderFieldKey(i); osnDW aN
if(sHeader!=null) 8>w/Es5
{ KJ-D|N,8@^
if(sHeader.equals("Content-Length")) yeW|Ux:
{ 'al-C;Z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >-:U
break; f>RPh bq|
} gs. K,xma
} DF-og*V
else 5Po.&eS
break; ZGS=;jM
} t!K|3>w
} tV<Au
catch(IOException e){e.printStackTrace ();} t!PFosFp
catch(Exception e){e.printStackTrace ();} 1e&`m~5K+
rm2TWM|
KLoHjBq
Utility.log(nFileLength); BtjsN22
pE=wP/#
8*|@A6ig
return nFileLength; > sUk6Z~
} al^ yCoB
_)p%
f'}23\>
//保存下载信息（文件指针位置） jdhhvoQ
private void write_nPos() ~#gVs*K
{ )2R:P`U
try{ Kyv$yf9
output = new DataOutputStream(new FileOutputStream(tmpFile)); rMI:zFS
output.writeInt(nStartPos.length); GSMP)8W
for(int i=0;i<nStartPos.length;i++) LNr2YRpyz
{ 8I@_X~R
// output.writeLong(nPos); `OBDx ^6F
output.writeLong(fileSplitterFetch.nStartPos); $#0%gs/x
output.writeLong(fileSplitterFetch.nEndPos); =LuA[g
} $ccI(J`zux
output.close(); 6~}=? sX4
} &<L+;k~P%
catch(IOException e){e.printStackTrace ();} ~ Iv[
catch(Exception e){e.printStackTrace ();} u[cbRn,W
} 4u"O/rt
YHE7`\l
Qs~;?BH&
//读取保存的下载信息（文件指针位置） AN^;~m^
private void read_nPos() K}Aaflq
{ d`v]+HK
try{ ty(F;M(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); cnI!}Bu
int nCount = input.readInt(); {lqnn n3
nStartPos = new long[nCount]; \b' <q
nEndPos = new long[nCount]; bZ0r/f,n$
for(int i=0;i<nStartPos.length;i++) c.NAUe_3
{ .lqo>Ta y
nStartPos = input.readLong(); rJR"[TTJ
nEndPos = input.readLong(); n#m )]YQC
} 2p@S-Lp
input.close(); >YLwWU<X
} :^px1
catch(IOException e){e.printStackTrace ();} @!K)(B;A0b
catch(Exception e){e.printStackTrace ();} 6n<:ph,h;
} Ll&Y_Ry
}"_S;[{d
%vMi kibI
private void processErrorCode(int nErrorCode) YsLEbue
{ B<+}_3.
System.err.println("Error Code : " + nErrorCode); IUI>/87u
} 3dC8MKPq0
m,Os$>{Ok
Z!tt(y\
//停止文件下载 rjfQ\W;}U
public void siteStop() x@Q}sW92
{ ]W]Vkkg]
bStop = true; sgFpZk
for(int i=0;i<nStartPos.length;i++) E@t^IGDr
fileSplitterFetch.splitterStop(); +\Rp N
MB:E/
M]eH JZ~v
} *p+%&z_<
} skr^m%W
//负责部分文件的抓取 ba|~B8rII[
**FileSplitterFetch.java _G[5S-0 [
*/ ck-wMd
package NetFox; hO\_RhsRy?
(5VP*67
O /aC%%
import java.io.*; spgY &OI;
import java.net.*; :MpIx&
K+PzTGWq^
q1Ah!9B
public class FileSplitterFetch extends Thread { N#Y4nllJ
P|c79
_ 4pBJOJQ6
String sURL; //File URL CShVJ:u+K\
long nStartPos; //File Snippet Start Position R)ejIKtY
long nEndPos; //File Snippet End Position hE+6z%A8
int nThreadID; //Thread's ID %I[(`nb
boolean bDownOver = false; //Downing is over .-fJ\`^mi
boolean bStop = false; //Stop identical k$# @_
FileAccessI fileAccessI = null; //File Access interface TRG"fVR
GIt;Y
Rm"lRkY4I[
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %0. o(U
{ Hz!+g'R!Gs
this.sURL = sURL; EzwYqw
this.nStartPos = nStart; /6b(w=pk
this.nEndPos = nEnd; JYs*1<
nThreadID = id; if r!ha+8!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Nmns3D
} }8 fG+H.
lB.P
U*1rA/"n
public void run() rB)m{)
{ 8Q?)L4.]
while(nStartPos < nEndPos && !bStop) p%_r0
{ (\>_{"*=
j=M_>
0g~WM
try{ SO3WOR`3
URL url = new URL(sURL); hPP+lqY[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8&f}GdZh
httpConnection.setRequestProperty("User-Agent","NetFox"); +u:8#!X$RD
String sProperty = "bytes="+nStartPos+"-"; "pQM$3n(
httpConnection.setRequestProperty("RANGE",sProperty); I Yj\t?,0
Utility.log(sProperty); FK;\Nce&
x]J{EA{+
_hK7hvM>
InputStream input = httpConnection.getInputStream(); o~2bk<]z
//logResponseHead(httpConnection); +.mIC:9
!nC Z,
B$_F)2%m;
byte[] b = new byte[1024]; ~`u?|+*BO
int nRead; c-n'F+fZ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^s_E|~U
{ _|x%M}O},
nStartPos += fileAccessI.write(b,0,nRead); %t`a-m
//if(nThreadID == 1) qdjRw#LS^q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m>jX4D7KZ
} {.DI[@.g
3@\vU~=P:
[AfV+$
Utility.log("Thread " + nThreadID + " is over!"); (/Hq8o-Fw
bDownOver = true; \bZbz/+D
//nPos = fileAccessI.write (b,0,nRead); M +~guTh
} WQ|d;[E
catch(Exception e){e.printStackTrace ();} lKxv SyD
} hnmFhJ !g
} u,*$n'l]
\/. Of]YQ
4cTJ$" v
//打印回应的头信息 to(OVg7_
public void logResponseHead(HttpURLConnection con) >/ECLP
{ 'h([Y8p{
for(int i=1;;i++) v$owG-_><
{ XGk8Ki3w
String header=con.getHeaderFieldKey(i); ^4`q%_vm
if(header!=null) WB"$NYB
//responseHeaders.put(header,httpConnection.getHeaderField(header)); tlA4oVII
Utility.log(header+" : "+con.getHeaderField(header)); N"2P&Ho]
else hm&{l|u{RU
break; 7Z93`A-=
} <~u.:x@ R
} b=Zg1SqV
6JSa:Q>,
kZWc(LwA
public void splitterStop() d]} 7]
{ zZ[SC
bStop = true; Z:&"Ax
} b^;19]/RW
t9zPJQlT}
\#lh b
} hUxpz:U*
cSnm\f
acRPKTs H
/* jgs kK
**FileAccess.java ]j}zN2[A
*//文件访问(定位，写) N_=7
package NetFox; F C2oP,
import java.io.*; J<H$B +;qR
m Wsegq4
1x V~EX
public class FileAccessI implements Serializable{ :2 n5;fp
[64K?l0&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 C;OU2,c,T
RandomAccessFile oSavedFile; GQ$0`?lp
long nPos; aGr(djD
(t&P.N/
/#G^?2oM
public FileAccessI() throws IOException GLv}|>W
{ 4O[5,
this("",0); k(3s^B
} uY5f mM9
aL-V9y
5lxC**NA
public FileAccessI(String sName,long nPos) throws IOException <(>v|5K0]
{ i6h:%n]Io
oSavedFile = new RandomAccessFile(sName,"rw"); SdYES5aES
this.nPos = nPos; :{E3H3
oSavedFile.seek(nPos); Fu^^Jex
} aEy_H-6f
<T+Pw7X
o{f n}
public synchronized int write(byte[] b,int nStart,int nLen) X:j&+d2g0/
{ ?P4`
int n = -1; jQ4Pv`
try{ &+J5GHt@
oSavedFile.write(b,nStart,nLen); F<Z"W}I+6
n = nLen; o//N"S.)
} kVe^g]F
catch(IOException e) s><RL]+{G+
{ +7sdQCO(Co
e.printStackTrace (); &julw;E
} ~5:]Oux
%[B &JhT
u8~.6]Ae
return n; ?$Uk[
} IgptiZ7~!
cJ&l86/l1
*[.+|v;A
} e1[kgp
+S<2d.&~
lh(A=hn"n
/* 5u~Ik c~
**SiteInfoBean.java kFw3'OZ,
*/ {1#5\t>9yD
package NetFox; Nr|.]=K)5n
<Zl0$~B:5
]\+bx=
public class SiteInfoBean { ~.VWrHC
&.K8cphj
jO3Q@N0_
private String sSiteURL; //Site's URL j8hb
private String sFilePath; //Saved File's Path bpzB}nEp
private String sFileName; //Saved File's Name RgRyo
private int nSplitter; //Count of Splited Downloading File FOquQr1cF
f2uog$Hk
v9x $`
public SiteInfoBean() n"@3d.21
{//nSplitter的缺省值为5 4w*F!E2H\}
//default value of nSplitter is 5 /+JCi6{sHS
this("","","",5); FK }x*d
} U%t:]6d&}
OAOG&6xu8
f*NtnD=rJ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter)
{ b?B"u^b!
sSiteURL= sURL; vTh-I&}:
sFilePath = sPath; d,8V-Dk+p
sFileName = sName; `axNeqM
this.nSplitter = nSpiltter; 3P^eD:) w
MR#jI
D7sw;{ns
} I@pnZ-5
L6r&Y~+/
;Zw!
public String getSSiteURL() !yojZG MB
{ tE(x8>5A:
return sSiteURL; E 7;KG^
} :}+U?8/"7
31w?bx !Pp
yc_(L-'n
public void setSSiteURL(String value) %/1`"M5ko
{ h+R}O9BD
sSiteURL = value; i:qc2#O:J
} 0}Kl47}aD
p KKn
_YmYy\g
public String getSFilePath() V=3NIw18
{ kYPowM
return sFilePath; YRW<n9=3
} jM2gu~
dWI/X
4w2V["?X1
public void setSFilePath(String value) f>#\'+l'
{ A5ktbj&gy<
sFilePath = value; >+#TsX{
} N^%[ B9D
a[lE9JA;|
F]M3/M
public String getSFileName() dAym)
{ Y5c( U)R8
return sFileName; ds5<4SLj
} -S)HB$8
:bLGDEC
Da?0B9'
public void setSFileName(String value) k(u W( 6
{ {;f`t3D
sFileName = value; @B7;
} Qy0bp;V/
!%T@DT=l&
&b"PjtU.X
public int getNSplitter() /5U?4l(6[f
{ /3FC@?l w4
return nSplitter; 5IVASqYp
} X k<X:,T
sJ3HH0e
_.?$~;7
public void setNSplitter(int nCount) kIU"-;5tP
{ hCW8(Zt
nSplitter = nCount; @ mtv2P`
} B quyPG"
} KhXW5hS1
X+P3a/T
;2#7"a^
/* W5J"#^kdF8
**Utility.java axXAy5
*/ *!C^L"i
package NetFox; Vi5RkUY]
M"X/([G
"=P@x|I
public class Utility { N{|N_}X`Y
He">kJx
}I05&/o.3p
public Utility() pOnZ7(
{ u'Mq^8
+]5JXt^
)JeiTh^
} M;\K+,
*Z)`:Gae
//线程睡眠 ApU5,R0
public static void sleep(int nSecond) h %MPppCEa
{ ?>4^e:
try{ .$99/2[90
Thread.sleep(nSecond); uh:
} |{t}ULc
catch(Exception e) DX4 95<6*
{ =1`
e.printStackTrace (); k9yA#
} O?8G
} xV<NeU
MttVgNV
//日志 <aL$d7
public static void log(String sMsg) X@|
{ ro^Y$;G
System.err.println(sMsg); bG2!5m4L
} 7v%~^l7:x
"b-6kM
R:^GNra;
public static void log(int sMsg) l}:9)nXA{
{ ~[ve?51
System.err.println(sMsg); cJi5\<b
} CO4*"~']t
} j&Z:|WniK
D{a{$Pr
/F/`?=1<$
/* i&"I/!3Q@
**TestMethod.java oBAD4qK
*/ A/BL{ U}
package NetFox; Z^h'&c#
|W\CV0L2
Vj~R6
public class TestMethod { I-fs*yzj;8
zx;x@";p
d:<{!}BR3
public TestMethod() tao3Xr^?
{ ///xx/weblogic60b2_win.exe /c3DltOdr
try{ ~~'XY(\L@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;uR8pz e
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -I\_v*nA
SiteFileFetch fileFetch = new SiteFileFetch(bean); mP3:Fc_G
fileFetch.start(); bLaD1rnGi
} l3l[jDa,2
catch(Exception e){e.printStackTrace ();} [dOPOA/d
F4">go
Z1^S;#v
} ?A,gDk/#
8.]dThaq
nCXIWLw
public static void main(String[] args) o?/N4$&5l
{ 9Z7o?S";
new TestMethod(); - DL/Hk_r
} KWN0$*4
} ke)3*.Y%C
点击下载更多相关资料