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)); h(@R]GUX
} oTCzYY
for(int i=0;i<nEndPos.length-1;i++) &|.hkR2k
{ <b d1
nEndPos = nStartPos[i+1]; PS=e\(6QC
} (#!]fF"!x
nEndPos[nEndPos.length-1] = nFileLength; V1SqX:;b&
} 7G5y)Qb
} p}3NJV
b!0DH[XKV
:n'yQ#[rn
//启动子线程 w66v\x~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; L[?nST18%
for(int i=0;i<nStartPos.length;i++) -<qxO
{ Y?yo\(Cdx
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }zFf0.82
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Vb@4(Q
nStartPos,nEndPos,i); mZ~qG5@/F
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "h=6Q+Ze
fileSplitterFetch.start(); AF^T~?t
} l~bKBz
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g(aZT#ii=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \dRzS@l
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", bfgz1 `u
nEndPos = " + nFileLength); ]3*P:$Rq
// fileSplitterFetch[nPos.length-1].start(); w*50ZS;N
A1^Ga5 B>
+TC1nkX
//等待子线程结束 N.Dhu~V
//int count = 0; .xO _E1Ku;
//是否结束while循环 \6sqyWI %
boolean breakWhile = false; A\K,_&x1Z
%*lp< D
'\`6ot8
while(!bStop) !(Krf
{ XCDSmZ
write_nPos(); _%Bz,C8
Utility.sleep(500); <FY&h#
breakWhile = true; }e 9!xA
G.g|jP'n
TyF{tuF
for(int i=0;i<nStartPos.length;i++) !X|k"km"
{ V/PAi.GZ
if(!fileSplitterFetch.bDownOver) $;2)s}ci
{ YOyp|%!
breakWhile = false; YNSyi@
break; ?aBj#
} lWWP03er!
} )MZC>:
if(breakWhile) A\z`c e!
break; jd 1jG2=f
Z!6UW:&~7
fc@'9-pt
//count++; ~,"N[Q
//if(count>4) !9;)N,
// siteStop(); GIT#<+"
} m@jge)O&D
y,E.SB
PWH^=K
System.err.println("文件下载结束！"); dAc ?O-~
} `0bP0^w
catch(Exception e){e.printStackTrace ();} ESTM$k}X
} gbDX7r-
{$d<1y^
j8++R&1f]
//获得文件长度 IA4N@ijRxh
public long getFileSize() |7"$w%2
{ n[,XU|2
int nFileLength = -1; +m)q%I>
try{ 1@>$ Gcc
URL url = new URL(siteInfoBean.getSSiteURL()); Y9Z]i$qS&k
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "Y;}GlE
httpConnection.setRequestProperty("User-Agent","NetFox"); m^V5*JIh
u.,Q4u|!
"?3`
int responseCode=httpConnection.getResponseCode(); 8w_7O>9
if(responseCode>=400) o.m:3!RW
{ ! zL1;d
processErrorCode(responseCode); 0|c}p([~
return -2; //-2 represent access is error D+JAK!W
} 29&bbfU
:"Y*<=x#2
_,haD)1g~
String sHeader; g^7MMlY%
E{?au]y$J
SJ?cI!=x
for(int i=1;;i++) o]ePP,
{ dY(;]sxFr
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); y7/F_{
//Utility.log(in.readLine()); AY,].Zg[
sHeader=httpConnection.getHeaderFieldKey(i); )5_jmW`n
if(sHeader!=null) 7fHc[,
{ s58C2
if(sHeader.equals("Content-Length")) +s++7<C
{ l(;Kij
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >R\lqLILb,
break; eJ0?=u!x
} GZip\S4Y
} rHjq1-t
else >UDd @
break; zFz10pH
} h[o6-f<D
} ,m_WR7!$E
catch(IOException e){e.printStackTrace ();} 8CbXMT
catch(Exception e){e.printStackTrace ();} CVNj-&vj
_P?s'HH
?e[lr>-
Utility.log(nFileLength); QnQOm""
U8.7>ENnP&
@$9'@")
return nFileLength; ZJPmR/OV_
} J(DN!
a2IgC25
bKg8rK u
//保存下载信息（文件指针位置） t>=fTkB
private void write_nPos() oVFnlA
{ w| `h[/,
try{ GZI`jS"lU
output = new DataOutputStream(new FileOutputStream(tmpFile)); I/Jb!R ~
output.writeInt(nStartPos.length); BTgG4F/)
for(int i=0;i<nStartPos.length;i++) tW WWx~k
{ .p0Clr!
// output.writeLong(nPos); *g?Po+ef%
output.writeLong(fileSplitterFetch.nStartPos); L:XC
output.writeLong(fileSplitterFetch.nEndPos); p sL?Y
} Xs: 3'ua
output.close(); Mmpfto%i
} }PTV] q%
catch(IOException e){e.printStackTrace ();} hxQqa 0B
catch(Exception e){e.printStackTrace ();} q`-;AG|xF
} C8 \5A8c
okbQ<{9
{~Rk2:gx
//读取保存的下载信息（文件指针位置） _S>JKz
private void read_nPos() yw];P o,
{ |PC*=ykT3
try{ &mb{.=
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); IiG6<|d8H
int nCount = input.readInt(); (1#J%
nStartPos = new long[nCount]; c%MW\qx
nEndPos = new long[nCount]; yu;P +G
for(int i=0;i<nStartPos.length;i++) vM5k_D
{ Oil?JI Hq
nStartPos = input.readLong(); nDHTV!]<
nEndPos = input.readLong(); @3zg=?3
} [eC2"&}
input.close(); V#iPj'*
} *s:(jDlv
catch(IOException e){e.printStackTrace ();} 5~>z h
catch(Exception e){e.printStackTrace ();} 3f,hw5R
} 0tXS3+@n=
lhqg$lb
RS8Hf~0G
private void processErrorCode(int nErrorCode) Y\No4w ^|d
{ A<??T[
System.err.println("Error Code : " + nErrorCode); "vOwd.(?N
} 2.l:O2<
[5SD_dN
sG F aL
//停止文件下载 nCdR EXw
public void siteStop() 8|\8O@
{ g\&g N
bStop = true; ]GW]dM
for(int i=0;i<nStartPos.length;i++) E>D_V@,/
fileSplitterFetch.splitterStop(); Jcrw#l8|C
Zg{KFM%
Pu"P9
} toBHkiuD
} ZZzMO6US0
//负责部分文件的抓取 KV0]m^@x
**FileSplitterFetch.java M 0U0;QJ
*/ J^Wa8Q;9lX
package NetFox; <h:x=
v0H@Eg_
Ezd_`_@R
import java.io.*; ~E2KZm
import java.net.*; %D\[*
!ug8SAOaz/
0tT(W^ho g
public class FileSplitterFetch extends Thread { pL/DZ|S3
r{L> F]Tw
f'EuY17w
String sURL; //File URL V{/?FO?E
long nStartPos; //File Snippet Start Position CVL3VT1j0
long nEndPos; //File Snippet End Position .$+#1-
int nThreadID; //Thread's ID Qp_isU
boolean bDownOver = false; //Downing is over KY$)#i
boolean bStop = false; //Stop identical s %j_H
FileAccessI fileAccessI = null; //File Access interface +M\`#i\g>
5m&9"T.w
iTgt}]L
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException e> e}vZlX
{ qNB<T('
this.sURL = sURL; 1WxK#c-)
this.nStartPos = nStart; #S!)JM|4wk
this.nEndPos = nEnd; rWa2pO
nThreadID = id; :LF?
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -#u=\8
} cUKE
g?goZPZB
x[~b2o
public void run() "O3tq=Q
{ E7j(QOf
while(nStartPos < nEndPos && !bStop) S"NqM[W
{ 2_HNhW
5F)C jQ
riY~%9iV'
try{ bzBEX mC
URL url = new URL(sURL); /?5 1D@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gc_:%ki
httpConnection.setRequestProperty("User-Agent","NetFox"); iVhJ t#_b
String sProperty = "bytes="+nStartPos+"-"; LM~[@_j
httpConnection.setRequestProperty("RANGE",sProperty); _|kxY'_[8
Utility.log(sProperty); 6m*QX+
AYqX|
tqE6>"jD
InputStream input = httpConnection.getInputStream(); %(3|R@G.
//logResponseHead(httpConnection); at#ja_ hd
+rd|A|hRq
)WNzWUfn=z
byte[] b = new byte[1024]; X`kk]8=
int nRead; aH)}/n
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) a!6{:8Zi0
{ 6iVxc|Ia
nStartPos += fileAccessI.write(b,0,nRead); &#{Z(h.de
//if(nThreadID == 1) n\Z!ff/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k+# %DK
} > kGGR
T"{>t
oR)Jznmi}
Utility.log("Thread " + nThreadID + " is over!"); R1adWBD>
bDownOver = true; @K &GJ
//nPos = fileAccessI.write (b,0,nRead); K -nF lPm\
} &47i"%
catch(Exception e){e.printStackTrace ();} (5$!MUS~9
} cM(:xv
} YqhAZp<
? &o2st
lHN5Dr
//打印回应的头信息 DrKP%BnS
public void logResponseHead(HttpURLConnection con) bkOv2tZ
{ :%lTU
for(int i=1;;i++) zGb|)A~,
{ hQ,ch[j'
String header=con.getHeaderFieldKey(i); =_.l8IYX$%
if(header!=null) kvL=> A
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [<lHCQXJ/
Utility.log(header+" : "+con.getHeaderField(header)); >!eAM )
else ;v}GJ<3
break; Rvqq.I8aC
} tURu0`](
} LC,F <>w1
:(/~:^!
Z)I+@2
public void splitterStop() FvaUsOy"
{ H*d9l2,KZS
bStop = true; x>**;#7)
} F%@A6'c
+%+tr*04O
1T"`vtR
} Ot4 Z{mA
u0JB\)(-/h
A=$04<nP8!
/* P{8iJ`rBG
**FileAccess.java 6hno)kd{=
*//文件访问(定位，写) I:=S0&%)
package NetFox; }5ret
import java.io.*; :NhO2L
"IZa!eUW
`LrHKb aP
public class FileAccessI implements Serializable{ ~8PZ5;g
_zR+i]9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ${<%" hR$
RandomAccessFile oSavedFile; {kA0z2Fe
long nPos; W\>fh&!)
QJZK|*
g{7.r-uu
public FileAccessI() throws IOException _'#n6^Us<
{ `xKp%9
this("",0); %vn|k[nD
} `fA@hK
NN%*b yK
3(="YbZ
public FileAccessI(String sName,long nPos) throws IOException +cJL7=V&
{ ZJnYIK
oSavedFile = new RandomAccessFile(sName,"rw"); *^\Ef4Lh
this.nPos = nPos; DF&(8NoX~
oSavedFile.seek(nPos); iJ ($YvF4
} =-0/k;^
Q0)#8Rcm
9"N~yKa`"K
public synchronized int write(byte[] b,int nStart,int nLen) XD!W: uvb
{ 034iK[ib"
int n = -1; Wvq27YK'
try{ )Oq|amvC
oSavedFile.write(b,nStart,nLen); S){)Z
n = nLen; KKb,d0T[
} s,"]aew
catch(IOException e) ^4y,W]JUDt
{ H[NSqu.s
e.printStackTrace (); a1g,@0s
} ADz ^\
6`&a&%,O
kYM~d07 V
return n; \Q {m9fE
} DRSr%d
;d@#XIS&-(
,dv+p&Tz2
} DMAIM|h
B~?*?Z'
Fh)IgzFj
/* i"1Mfz~e
**SiteInfoBean.java '<gI8W</
*/ mbKZJ{|4s
package NetFox; UZWioxsKr+
v|Pv 03%?7
`A,-@`p
public class SiteInfoBean { ; 8_{e3s
2\)xpOj
&r[`>B{tP
private String sSiteURL; //Site's URL zU,9T
private String sFilePath; //Saved File's Path .zr-:L5{
private String sFileName; //Saved File's Name e-~N"
private int nSplitter; //Count of Splited Downloading File 2\R'@L*
FK^p")i
d}Xr}
public SiteInfoBean() EHSlK5bD,
{//nSplitter的缺省值为5 jxP;>K7O
//default value of nSplitter is 5 I^* Nqqq
this("","","",5); _aq8@E~
} '%>=ZhO
#./fY;:cj
$&Gu)4'+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) xv46r=>
{ BfXgh'Z~
sSiteURL= sURL; {5A2&
sFilePath = sPath; SDL7<ZaE
sFileName = sName; yyR0]NzYUD
this.nSplitter = nSpiltter; O6@j &*jS
QER?i;-wb
M|VyV(f
} X enE^e+9
*=) cQeJ
t1]K<>g
public String getSSiteURL() G%BjhpL
{ "RedK '7g
return sSiteURL; $5>e
} c7?_46J
~cWAl,(B<F
1v#%Ei$6`t
public void setSSiteURL(String value) rDl*d`He!
{ XWnVgY s
sSiteURL = value; y@1+I~@
} ?llXd4
r`$OO,W
vjLJinJ/
public String getSFilePath() iyN:%ofh
{ "_P;2N6
return sFilePath; Q[Z8ok
} w?3p';C
0mpX)S
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public void setSFilePath(String value) ycc4W*]
{ #||}R[~P"
sFilePath = value; Y1L[;)Hn
} ,ZaRy$?
j~"Q3P;V
R$v[!A+:'
public String getSFileName() 2iHUZzz\
{ dW_KU}
return sFileName; \@Ts+7%
} <qtr
ZLc -RM
~Uu4=
public void setSFileName(String value) ,%6P0#-
{ &]g}u5J!=
sFileName = value; +j#+8Ze
} =FlDb 5t{
7z/|\D_{
C'G/AU
public int getNSplitter() k@\ iGqo
{ *7:>EP
return nSplitter; 4Fa~Aog
} H[{F'c[e
3("_Z%
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public void setNSplitter(int nCount) 81](T<
{ kv]~'Srk
nSplitter = nCount; 1G"z<v B
} YO#M/%^j
} Q8C_9r/:N>
C`K?7v3$m
w&X<5'GM
/* xRJ\E }/7
**Utility.java -1 FPkp
*/ u&1q [0y
package NetFox; cU RkP`
+vvv[
hwu]Er.gn
public class Utility { RdWRWxTn8+
<_h~w}
O#b6mKPt;t
public Utility() N+++4;
{ 'GB.UKlR
8hXl%{6d3
,eOB(?Ku
} `lQ3C{}
LyZ.l*h%=m
//线程睡眠 t,,k
public static void sleep(int nSecond) R,gR;Aarw
{ .}&`TU
try{ Cf TfL3(J
Thread.sleep(nSecond); 'w!Cn>
} _/F7?^j
catch(Exception e) V}bjK8$$
{ AB=daie
e.printStackTrace (); --PtZ]Z
} }0eF~>Df
} &{ay=Mj
Z9:-rcr
//日志 B{|8#jqY
public static void log(String sMsg) 3_txg>P"
{ V`X2>-Ex
System.err.println(sMsg); |*:'TKzNS
} o4j[p3$
<PapskO>
@*OZx9
public static void log(int sMsg) Rd2qe /
{ '3_]Gu-D
System.err.println(sMsg); DAS/43\
} wN`jE0 {
} hHN'w73z
Q?e*4ba
)#P; x"
/* q-.,nMUF
**TestMethod.java xGu r
*/ ]4~lYuI4
package NetFox; )T';qm0w
5V6G=H
t?q@H8
public class TestMethod { ' qWALu
21 O'M
Q o?O:
public TestMethod() kgnmGuka
{ ///xx/weblogic60b2_win.exe M*z~gOZ
try{ /]=C{)8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); P\w\N2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); v\!Be[ ?
SiteFileFetch fileFetch = new SiteFileFetch(bean); afv~r>q(-
fileFetch.start(); ]DOX?qI i
} 8)O[Aq::
catch(Exception e){e.printStackTrace ();} @W vatD V
gXYI\.
}!;s.[y
} ,8:(OB|a
XM1WfjE\
'SCidN(n
public static void main(String[] args) ]vgB4~4#LP
{ nN*w~f"
new TestMethod(); Fz1_w$^
} 9{-EJ)
} yHs-h
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