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)); j=pg5T
} K Zg NL|
for(int i=0;i<nEndPos.length-1;i++) O)W+rmToI
{ t<dFH}U`w
nEndPos = nStartPos[i+1]; Jt}`oFQ5l
} :2KPvp7?
nEndPos[nEndPos.length-1] = nFileLength; 8Dl(zYK;
} 1BmKwux:
} ITl>HlS
p9jC-&:
yT:2*sZRc
//启动子线程 WZ`i\s1#
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~rb]u Ny-
for(int i=0;i<nStartPos.length;i++) Qq6'[Od
{ PK|qiu-O&*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bLS10^g5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6&]Z'nW0k
nStartPos,nEndPos,i); VsTgK
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); auGK2i
fileSplitterFetch.start(); BEax[=&W
} |(l]Xr&O
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r<kgYU`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); LL);Ym9d
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6|lsG6uf
nEndPos = " + nFileLength); 5mV!mn:H:
// fileSplitterFetch[nPos.length-1].start(); 8a)4>B
9_==C"F
1?w=v|b:P)
//等待子线程结束 !4<D^eh
//int count = 0; ^O<v'\!z-
//是否结束while循环 `oe=K{aX
boolean breakWhile = false; //N="9)@
YFu>`w^Y
]gX8z#*k
while(!bStop) 3~R,)fO;
{ /$clk=
write_nPos(); :' 5J[]J
Utility.sleep(500); y=pW+$k
breakWhile = true; P(yLRc
Wgs6}1bg
sMAj?]hI$
for(int i=0;i<nStartPos.length;i++) Q7e4MKy7
{ 6p@[U>`
if(!fileSplitterFetch.bDownOver) nCwA8AG
{ =c 9nC;C
breakWhile = false; '4d4i
break; ysi=}+F.
} IAzFwlO9
} I++ Le%w
if(breakWhile) .Y2Hd$rs
break; NRG06M
q_^yma
$Tv~ *|a
//count++; ,d*1|oUw
//if(count>4) A",}Ikh='`
// siteStop(); oj.J;[-
} G:1QXwq\j
]#DCO8Vk
u(yN81
System.err.println("文件下载结束！"); Ohj^Z&j
} b00$3,L
catch(Exception e){e.printStackTrace ();} EdqB4-#7
} _t"[p_llo
fe<7D\Sp@
Y=|20Y\K
//获得文件长度 2%fzRXhu%
public long getFileSize() ~tTn7[!
{ s>G]U)d<'
int nFileLength = -1; W;T0_=
try{ D^h! ].3 T
URL url = new URL(siteInfoBean.getSSiteURL()); F0&ubspt\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WJ-.?
httpConnection.setRequestProperty("User-Agent","NetFox"); AvZ5?rN$
Zgp9Uu}"
a_/4^+
int responseCode=httpConnection.getResponseCode(); doTbol?+
if(responseCode>=400) 7xB]Z;:
{ >Vx_Xv`Jwb
processErrorCode(responseCode); ]v5/K
return -2; //-2 represent access is error )uAY_()/
} DazoY&AWE
&n8Ja@Y]
Fab]'#1q4
String sHeader; bBc<p{
KF(y`(8f
` ;mQ"lO
for(int i=1;;i++) #hn
{ R+ \%
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); d0}(d Gl
//Utility.log(in.readLine()); K"t?
sHeader=httpConnection.getHeaderFieldKey(i); raOuD3
if(sHeader!=null) N LQ".mM+
{ f U=P$s
if(sHeader.equals("Content-Length")) AfhJ6cSIE
{ aaf}AIL.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); V:j^!*
break; E<tR8='F
} Eo^m; p5
} "(W;rl
else ha;fxM]
break; +1yi{!j1
} L?;UcCB
} ,<K+.7,)E
catch(IOException e){e.printStackTrace ();} ZY7-.
catch(Exception e){e.printStackTrace ();} %E#Ubm!
b==jlYa=
qov<@FvE0
Utility.log(nFileLength); T=~d.&J
/N%i6t<xU
li?@BHEf
return nFileLength; +\%]<YO
} 6 %aaK|0
lr;ubBbT
H;_Ce'oU(
//保存下载信息（文件指针位置） ct|0zl~
private void write_nPos() {*n<A{$[ m
{ [G|(E
try{ $ S3b<]B
output = new DataOutputStream(new FileOutputStream(tmpFile)); Ap?,y?
output.writeInt(nStartPos.length); \kUQe-:he
for(int i=0;i<nStartPos.length;i++) _IOUhMo
{ 3^&`E}r
// output.writeLong(nPos); k ?6d\Q
output.writeLong(fileSplitterFetch.nStartPos); 2`;XcY4A
output.writeLong(fileSplitterFetch.nEndPos); 1}c/l<d
} ~.G$0IJY
output.close(); mE{QTZS
} H[s+.&^
catch(IOException e){e.printStackTrace ();} #mUQ@X@K
catch(Exception e){e.printStackTrace ();} C4PT(cezR
} #6#n4`%ER
@+zWLq!1pB
W//+[
//读取保存的下载信息（文件指针位置） *)B \M>
private void read_nPos() *re?V9
{ j3%Wrt
try{ A)!W VT&2A
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); RAhDSDf
int nCount = input.readInt(); WzR)R9x]
nStartPos = new long[nCount]; ^J-Xy\X
nEndPos = new long[nCount]; |[5;dt_U/
for(int i=0;i<nStartPos.length;i++) 2 KHT!ik
{ n2-+.9cY
nStartPos = input.readLong(); ami>Pp
nEndPos = input.readLong(); 3SbZD
} 2+)h!y]
input.close(); t>%b[(a
} IFr"IOr'l
catch(IOException e){e.printStackTrace ();} _hl| 3 eW5
catch(Exception e){e.printStackTrace ();} r90tXx
} `EMGrw_
=ZU!i0 K
W\Scak>
private void processErrorCode(int nErrorCode) kk<%VKC
{ !wd wo0
System.err.println("Error Code : " + nErrorCode); wDoCc:
} c-NUD$
}yrs6pQ
&I)tI^P}
//停止文件下载 g%]<sRl:-
public void siteStop() PCgr`($U
{ ]Z\W%'q+
bStop = true; l}-k>fug
for(int i=0;i<nStartPos.length;i++) ,MJddbcg
fileSplitterFetch.splitterStop(); [cEGkz
# SCLU9-
&,PA+#
} .WN&]yr,
} |zfFB7}v
//负责部分文件的抓取 y_W?7S
**FileSplitterFetch.java @VOegf+N
*/ NRG~ya >
package NetFox; ?xMTO
6ZI7V!k
gU&+^e >
import java.io.*; MTl @#M
import java.net.*; ^)Y3V-@t
&Q"vXs6Gt
N GnE
public class FileSplitterFetch extends Thread { bvZD@F`2
3;}YW^oXq
"#0P*3-c
String sURL; //File URL yr>J^Et%_
long nStartPos; //File Snippet Start Position p}!)4EI=
long nEndPos; //File Snippet End Position O\;Lb[`lb
int nThreadID; //Thread's ID 3HP { a
boolean bDownOver = false; //Downing is over <bCB-lG*Kb
boolean bStop = false; //Stop identical 6K8v:yYPa
FileAccessI fileAccessI = null; //File Access interface 6?US<<MQ
_'Vo3b
uw8g%
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7u^wO<
{ bL0]Yuh
this.sURL = sURL; ~MB)}!S:
this.nStartPos = nStart; $X.F=Kv
this.nEndPos = nEnd; ?XyrG1('
nThreadID = id; }lPWA/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |SMigSu r`
} #>_fYjT
}2BNy9q@
hF^JSCDz l
public void run() >zJkG9a
{ yCkWuU9
while(nStartPos < nEndPos && !bStop) ^hEN
{ "3Dnp?gB
r:0RvWif
tZ@&di:-F
try{ hTby:$aCg
URL url = new URL(sURL); J'=s25OWU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n 78!]O
httpConnection.setRequestProperty("User-Agent","NetFox"); \?e2qu/ C
String sProperty = "bytes="+nStartPos+"-"; 3bC-B!{;g
httpConnection.setRequestProperty("RANGE",sProperty); f]Aa$\@b
Utility.log(sProperty); j;j~R3B
fWfhs}_
13 JG[,w
InputStream input = httpConnection.getInputStream(); ;2fzA<RkK
//logResponseHead(httpConnection); K]>4*)A:
{nA+-=T
~KGE(o4p
byte[] b = new byte[1024]; "k [$euV
int nRead; $[cB6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) UDcr5u eKn
{ IWN18aaL?
nStartPos += fileAccessI.write(b,0,nRead); Gk58VODo
//if(nThreadID == 1) VOATza`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A9DFZZ0
} at*DYZBjDB
+dq2}gM
wp~KrUlR
Utility.log("Thread " + nThreadID + " is over!"); T72Z<h|<
bDownOver = true; Avljrds+7
//nPos = fileAccessI.write (b,0,nRead); zKYN5|17
} h=YTgJ
catch(Exception e){e.printStackTrace ();} <R2SV=]Sq#
} i+I.>L/S
} n3/Bs
l_ x jsu
1dp8'f5^
//打印回应的头信息 PDgZb
public void logResponseHead(HttpURLConnection con) O6-';H:I]L
{ :u@ w;
for(int i=1;;i++) v,rKuvc'
{ /!"sPtIh
String header=con.getHeaderFieldKey(i); yQu/({D
if(header!=null) 5|bfrc
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~U8#yo
Utility.log(header+" : "+con.getHeaderField(header)); 9K&YHg:1
else )r*F.m{&:
break; |N^8zo :
} ;uZq_^?:9&
} B~<bc
y?}<SnjP:
a)+*Gf7?
public void splitterStop() ), VF]
{ 9a1R"%Z
bStop = true; \)MzUOZn
} VeFfkg4
V5jy,Qi)
b|k(:b-G&.
} pwVGe|h%,
J<cY'?D
.k!2{A
/* a*_" nI&lr
**FileAccess.java sC :.}6
*//文件访问(定位，写) Y{4nBu
package NetFox; #iD`Bg!VXc
import java.io.*; PEKXPFN
V3 ~&R:Z9e
J}@.f-W\j
public class FileAccessI implements Serializable{ _t X1z^
J6zU#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 C6tfFS3bq
RandomAccessFile oSavedFile; 7.yCs[Z
long nPos; hx~rq`{
J?&%fI
6LT.ng
public FileAccessI() throws IOException bSTTr<W
{ z=rSb4"W
this("",0); >dDcm
} P!&yYR\
S*ie$}ZX
7$L*nf
public FileAccessI(String sName,long nPos) throws IOException `P;3,@ e
{ =$kSn\L,
oSavedFile = new RandomAccessFile(sName,"rw"); ~>%%kQt
this.nPos = nPos; cS#| _
oSavedFile.seek(nPos); >(Wt
} [/J(E\9
6*tky;
7u%OYt D E
public synchronized int write(byte[] b,int nStart,int nLen) "@xL9[d
{ 4%jQHOZ
int n = -1; cm>+f^4?n
try{ ~^g*cA t}
oSavedFile.write(b,nStart,nLen); %W2 o`W$
n = nLen; S)^eHuXPI
} jyRz53
catch(IOException e) 'z};tIOKJk
{ c8o2* C$
e.printStackTrace (); -}>H3hr
} > mP([]
AD'c#CT
hi ),PfAV
return n; ]vCs9* |B
} GkdxwuRw
:-+j,G9t
.7Itbp6=R
} qi1#s,
X'7MW? q@
Q6PMRG}/o
/* 3+vMi[YO
**SiteInfoBean.java h& Ezhv2
*/ <ZoMKUuB
package NetFox; ^%33&<mB}
6.3qux9
#4& <d.aw'
public class SiteInfoBean { -D_xA10
jXyK[q&O&
kl5Y{![/&f
private String sSiteURL; //Site's URL RXhT{Ho(>
private String sFilePath; //Saved File's Path d]^\qeG^p
private String sFileName; //Saved File's Name B}d)e_uLj
private int nSplitter; //Count of Splited Downloading File XiyL563gh
,LDdL
#4^D'r>pJ
public SiteInfoBean() ~H626vT37
{//nSplitter的缺省值为5 *iVv(xXgN
//default value of nSplitter is 5 <TEDs4 C
this("","","",5); 8H{9
} 8-Z|$F"
>td\PW~X
<IQ}j^u-F
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e[.JS6
{ hJoh5DIE95
sSiteURL= sURL; 4~0@(3
sFilePath = sPath; r 4+%9)
sFileName = sName; -lI6!a^
this.nSplitter = nSpiltter; 212
YM +4:P2
D^H4]7wG@
} SrvC34<7
ia%U;M
'# J/e0o@
public String getSSiteURL() yxy~N\0
{ .$r7q[
return sSiteURL; {&)E$M
} {9h`h08?z
RV6|sN[x>
@?[}\9dW
public void setSSiteURL(String value) |\h<!xR
{ }H9V$~}@-
sSiteURL = value; $7&t`E)qY
} M_#^zo "x
S(5&%}QFQ
f:/"OCig
public String getSFilePath() @@+BPLl
{ )9V8&,
return sFilePath; C,dRdEB>
} @t,Y<)U
?~rz'Pu~
'<hgc
public void setSFilePath(String value) fzjZiBK@
{ [hKt4]R
sFilePath = value; Znh)m
} W0N*c*k
2[Bw+<YA`
|&0Cuwt
public String getSFileName() #9@UzfZAwT
{ -f%J_`
return sFileName; .Gnzu"lod
} )ZDqj
1H7bPl|
JcI~8;Z@Z~
public void setSFileName(String value) Zl=IZ?F
{ 'FmnlC1
sFileName = value; 6kHb*L Je
} #s|/5[i
>I*uo.OF
0D^c4[Y'l
public int getNSplitter() JReJlDu
{ 5,K*IH
return nSplitter; vo]$[Cp|4
} V=5v7Y3(j
Qon>[<]B
HT=-mwa_]
public void setNSplitter(int nCount) 2)+ddel<Z
{ bRK[u\,
nSplitter = nCount; 0z=^_Fb
} rn%q*_3-o
} WRfhxl
3^p;'7x
]ZM-c~nL
/* |j~{gfpSE
**Utility.java h<IPV'1
*/ )+12r6W
package NetFox; `ouCQ]tKz
Nd61ns(N
e:zuP.R
public class Utility { Q%^!j_#
6Bn%7ZBv
">"B
public Utility() qgZN&7Nn:
{ ~ZZJ/Cu
hYU4%"X
Y|N.R(sAs&
} 8YwSaBwO
p& +w
//线程睡眠 Tn(c%ytN
public static void sleep(int nSecond) iP+3)
{ V75P@jv5J
try{ *S{fyYyM
Thread.sleep(nSecond); xBKis\b
} /&g~*AL
catch(Exception e) ]R8JBnA
{ 7q|51rZz
e.printStackTrace (); 8d*W7>rq
} jp P'{mc
} Wd/m]]W8Q
r@]iy78 j
//日志 .3< sv
public static void log(String sMsg) ?D`h[ai
{ 2vx1M6a)L
System.err.println(sMsg); -@yu 9=DT
} n>:|K0u"
29AWg(9?aS
LKe~
public static void log(int sMsg) t{RdqAF
{ 8:)itYE
System.err.println(sMsg); eJtfQ@?
} (b>B6W\&
} x#,nR]C
"qvJ-Y
hTK6N
/* M|uWSG
**TestMethod.java 8S*W+l19f
*/ %:hU:+G E
package NetFox; v\b@;H`
w@"l0gm+u[
0z:BSdno
public class TestMethod { e!JC5Al7
c6Z\ecH9
3pk`&'
public TestMethod() /5 6sPl 7}
{ ///xx/weblogic60b2_win.exe ,CA3Q.y>|
try{ ]\Q9j7}37+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %+e% RZ3
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Or*e$uMIY
SiteFileFetch fileFetch = new SiteFileFetch(bean); i*-L_!cc:
fileFetch.start(); H_<hZUB
} >lIQM3
catch(Exception e){e.printStackTrace ();} ~k[q:$T
=[T_`*s&
La#otuw+?
} STY\c5
:r,o-D
f+iM_MI
public static void main(String[] args) ^t#W?rxp&
{ +U];
new TestMethod(); 9 9S-P}xd
} `U[s d*C"
} ?ta(`+"
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