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)); \.7O0Q{
} 8=h$6=1S
for(int i=0;i<nEndPos.length-1;i++) Ie%twc
{ \x_fP;ma=_
nEndPos = nStartPos[i+1]; v<qiu>sbz}
} $2j?Z.yEG
nEndPos[nEndPos.length-1] = nFileLength; :jp4 !0w
} d=B DR^/wA
} #FfUkV
j4B|ktf
cPgz?,hE
//启动子线程 ? <.U,
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )FG<|G(
for(int i=0;i<nStartPos.length;i++) uJP9J U
{ K{)YnY_E;
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r ]cC4%in
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 75pz' Cb
nStartPos,nEndPos,i); LBlaDw
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EFgs}BV_9
fileSplitterFetch.start(); jJmg9&^R
} Gv};mkX[N
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NI^[7.2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Gu3'<hTlxd
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !PfIe94{`
nEndPos = " + nFileLength); mQOYjy3
// fileSplitterFetch[nPos.length-1].start(); fJ?$Z|
v&>TU(x\H
sH>Z{xjr
//等待子线程结束 Q7]VB p4
//int count = 0; $^2 j#]uX
//是否结束while循环 ;b""N,
boolean breakWhile = false; A~!3svJW
U-$ B"w&
I<I?ks
while(!bStop) $z9z'^HqO
{ A@wRP8<GKj
write_nPos(); C(-bh]J
Utility.sleep(500); q1nGj
breakWhile = true; GA{Q6]B
3f{%IU(z
ZcXqH7`r
for(int i=0;i<nStartPos.length;i++) p[QF3)9F
{ od- 0wJN-m
if(!fileSplitterFetch.bDownOver) GB+U>nf
{ L7jMpz&
breakWhile = false; &\\iD :J
break; 9's/~T
} nD\X3g`V
} UN&b]vg
if(breakWhile) iaR^]|7_
break; :;u~M(R
ba?]eK
fN8|4
//count++; y?-wjJS>
//if(count>4) ?Rl?Pp=>
// siteStop(); ##7,
} .Lrdw3(
LB1.N!q1
&Jj^)GBU
System.err.println("文件下载结束！"); *xs8/?
} p&F=<<C
catch(Exception e){e.printStackTrace ();} q_8qowu"
} Llf>C,)
#gOITXKs
%Gn(b1X
//获得文件长度 3\FiQ/?
public long getFileSize() nMcd(&`N
{ l}X3uyS
int nFileLength = -1; T7YzO,b/
try{ r+HJ_R,5A
URL url = new URL(siteInfoBean.getSSiteURL()); >P5 EW!d
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `xkJ.,#Io
httpConnection.setRequestProperty("User-Agent","NetFox"); -t %.I=|
\z8TYx@
^HKxaW9W
int responseCode=httpConnection.getResponseCode(); uJG^>B?`b
if(responseCode>=400) 4qjY,QJ
{ GZ@!jF>!u
processErrorCode(responseCode); WJ\YKXG
return -2; //-2 represent access is error bTKzwNx
} !.iA^D//]
:$[m[y7i
<?Fgm1=o
String sHeader; NS=puo
bn^^|i
Cs%'Af
for(int i=1;;i++) ~@R=]l"
{ x&)P)H0vn
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); jKQnox+=
//Utility.log(in.readLine()); e&F,z=XJ}
sHeader=httpConnection.getHeaderFieldKey(i); LP_!g
if(sHeader!=null) 1kl4X3q6
{ Oa7`Y`6
if(sHeader.equals("Content-Length")) $K\\8$Z
{ blaxUP:
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "xS",6Sy
break; 2hf]XV\
} Yk<?HNf
} Ik=KEOz
else )R{4"&&2
break; "S#0QH%5
} 6}Y^X
} ,_YCl09p(
catch(IOException e){e.printStackTrace ();} tTF/$`Q#*
catch(Exception e){e.printStackTrace ();} >F,~QHcz
sP5PYNspA
2#6yO`?uo
Utility.log(nFileLength); lGjmw"/C
_l}&|:
!K(0)~u
return nFileLength; y| @[?B
} #12PO q
v2JC{XqrI
04:^<n+{
//保存下载信息（文件指针位置） kP6g0,\|a|
private void write_nPos() eNu`\
{ 0l^-[jK)
try{ RH6qi{)i!
output = new DataOutputStream(new FileOutputStream(tmpFile)); }I,]"0b
output.writeInt(nStartPos.length); <G\q/!@_
for(int i=0;i<nStartPos.length;i++) f]%$HfF@
{ 5"^$3&)
// output.writeLong(nPos); s+C&\$E
output.writeLong(fileSplitterFetch.nStartPos); Bz9!a k~4
output.writeLong(fileSplitterFetch.nEndPos); hUB_[#8#
} Z!~~6Sq
output.close(); ,V.X-`Y
} >UZfi u
catch(IOException e){e.printStackTrace ();} V8`t7[r
catch(Exception e){e.printStackTrace ();} !95ZK.UT
} E]6;nY?
vkASp&a
e6QUe.S
//读取保存的下载信息（文件指针位置） 6*GY%~JbD
private void read_nPos() ,~JxYh
{ -fT]}T6=
try{ L@t<%fy@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); u z4P
int nCount = input.readInt(); *s S7^OZ*
nStartPos = new long[nCount]; HKb8z@;%@
nEndPos = new long[nCount]; ;6U=fBp7<
for(int i=0;i<nStartPos.length;i++) xuv%mjQ
{ x=5k74
nStartPos = input.readLong(); a~9U{)@F
nEndPos = input.readLong(); l}5@6;}
} iaLsIy#h
input.close(); k3}|^/bHJ
} MHpPb{^
catch(IOException e){e.printStackTrace ();} 7^ITedW@
catch(Exception e){e.printStackTrace ();} /3L1Un*
} !G90oW
S c_*L<$
_K_!(]t
private void processErrorCode(int nErrorCode) (UAa
{ z\sy~DM;>
System.err.println("Error Code : " + nErrorCode); [YpSmEn}Y
} +=)< Su.
cWA9n}Z
#Ne<=ayS
//停止文件下载 \rF6"24t6
public void siteStop() Nh^T,nv*l
{ p&>*bF,
bStop = true; E*:!G
for(int i=0;i<nStartPos.length;i++) o )G'._
fileSplitterFetch.splitterStop(); _*>bf G
O={4 >>F
JN .\{ Y
} xdd7OSc0{
} m$ )yd~
//负责部分文件的抓取 o+4/L)h
**FileSplitterFetch.java r/$+'~apTk
*/ nL%;^`*8
package NetFox; D^baXp8
j6%X
ug'I:#@2
import java.io.*; >XcbNZV
import java.net.*; *p`0dvXG2
o]t6u .L
w},' 1
public class FileSplitterFetch extends Thread { @zL)R b%P$
I= G%r/3
W=c7>s0>
String sURL; //File URL w,bILv)
long nStartPos; //File Snippet Start Position X^r5su?
long nEndPos; //File Snippet End Position iS&~oj_-%
int nThreadID; //Thread's ID EgOAEv
boolean bDownOver = false; //Downing is over *Z>Yv37P
boolean bStop = false; //Stop identical bY|%ois4
FileAccessI fileAccessI = null; //File Access interface R7;SZo
+0rMv
VUC
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException h!5^d!2,
{ O# .^}
this.sURL = sURL; >ygyPl ;1s
this.nStartPos = nStart; ,],"tzKtE
this.nEndPos = nEnd; S~d_SU~>`
nThreadID = id; T)&J}^j
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \HLI y
} '@>FtF[Gu
)SQ*"X4"
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public void run() Vc.A<(
{ 7Bm 18
while(nStartPos < nEndPos && !bStop) _QbLg"O
{ u*B.<GmN
@[u!
GenkYtS
try{ *Dtwr
URL url = new URL(sURL); @qmONQ eb
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %VOn;_Q*B
httpConnection.setRequestProperty("User-Agent","NetFox"); py`RH)
String sProperty = "bytes="+nStartPos+"-"; -CfGWO#Gbx
httpConnection.setRequestProperty("RANGE",sProperty); agQzA/Xt
Utility.log(sProperty); sfNXIEr^
#qXE[%
gvvl3`S{
InputStream input = httpConnection.getInputStream(); q$z#+2u
//logResponseHead(httpConnection); oEbgyT gB
2 *IF
g9|B-1[
byte[] b = new byte[1024]; 'c<vj jIg
int nRead; ^prseO?A
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) bq[j4xH0X
{ RmxgCe(2a
nStartPos += fileAccessI.write(b,0,nRead); p.^mOkpt
//if(nThreadID == 1) N]R<EBq
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ez=$]cln
} Yr5A,-s
/AV [g^x2
Hy5_iYP5
Utility.log("Thread " + nThreadID + " is over!"); G,M &z>ub0
bDownOver = true; S>OfUrt
//nPos = fileAccessI.write (b,0,nRead); 3dfG_a61y
} )QE7$|s
catch(Exception e){e.printStackTrace ();} vK6YU9W~J
} QW#]i
} `)e;bLP
V2sWcV?
eT1b88_
//打印回应的头信息 ,Q4U<`ds!
public void logResponseHead(HttpURLConnection con) In^MZ)?
{ x3=W{Fv@4
for(int i=1;;i++) 4*MjDb
{ s (|T@g
String header=con.getHeaderFieldKey(i); F>jPr8&
if(header!=null) Be}e%Rk
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B!GpD@U
Utility.log(header+" : "+con.getHeaderField(header)); <J-bDcp
else BT;hW7){9
break; 8^M5k%P
} r)Ts(#Z
} L0uvRge
BM=`zGh"
Z l.}=
public void splitterStop() N ?Jr8
{ :J]S+tQ)
bStop = true; j*f%<`2`j
} *%1:="W*|
uMa: GDh7
<_@ K4zV
} g0Qg]F5D~
2Fi>nJ
A]R7H1
/* !t "uNlN
**FileAccess.java loN!&YceW
*//文件访问(定位，写) KJWYG^zI
package NetFox; [0.>:wT
import java.io.*; DR3M|4[
Hn)K;?H4
c\FyX\i
public class FileAccessI implements Serializable{ lnL&v'{
nR4L4tdS
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 u^a\02aV[
RandomAccessFile oSavedFile; 3U<\y6/
long nPos; uA=6 HpDB
#@H{Ypn`
*V#v6r7<Y/
public FileAccessI() throws IOException iKv`[k
{ Ht+ng
this("",0); f/Km$#xOr
} g0I<Fan
8yz A W&q
Pc{D,/EpR
public FileAccessI(String sName,long nPos) throws IOException BL0WI9
{ SFoF]U09
oSavedFile = new RandomAccessFile(sName,"rw"); ac>}$Uw)
this.nPos = nPos; "BjQs<]%sF
oSavedFile.seek(nPos); k/AcXU%O+
} @iB**zR/
qyl~*r*
KIn^,d0H
public synchronized int write(byte[] b,int nStart,int nLen) St,IWOmq"
{ FW#Lf]FJ
int n = -1; ehCc N4V(
try{ Ek_k_!
oSavedFile.write(b,nStart,nLen); 2T5@~^:7u
n = nLen; /' L20aN2
} ~6U@*Svk
catch(IOException e) I@cKiB
{ WhE5u&`
e.printStackTrace (); 9 U1)sPH;
} KQi9qj
\sHM[nF0
oV?tp4&
return n; X^%I 3
} o;FjpZ
;w4rwL
,iCd6M{
} 8"wA8l.
NrVQK}%K
+;#hED;8
/* /7@@CG6b
**SiteInfoBean.java M7yJ2u<Ty
*/ @SPmb o
package NetFox; aFo%B; 8m
[=e61Z
L"zOa90ig
public class SiteInfoBean { ,!kyrk6
51`w.ri
+x G](?
private String sSiteURL; //Site's URL )U<4ul
private String sFilePath; //Saved File's Path $>/J8iB
private String sFileName; //Saved File's Name z-[Jbjhd
private int nSplitter; //Count of Splited Downloading File '7>Vmr6
DBCL+QHA
AEPgQ9#E
public SiteInfoBean() oLruYSaD
{//nSplitter的缺省值为5 wVE"nN#
//default value of nSplitter is 5 K!|=)G3.`
this("","","",5); Yc:b:\0}F6
} !SJmu}OB]
RfN5X}&A
z-7F,$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) m>:%[vm
{ \nkqp
sSiteURL= sURL; Y141Twjvd
sFilePath = sPath; 5`x9+XvoN
sFileName = sName; e-qr d
this.nSplitter = nSpiltter; rUlpo|B
l*'8B)vN2
[FiXsYb.8
} C&e
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bs+KcY:N]
public String getSSiteURL() `R:<(:
{ ^~BJu#uVyy
return sSiteURL; zztW7MG2lQ
} !+>yCy$~_
}O1F.5I1
}=f}@JlFB
public void setSSiteURL(String value) pQVi&(M
{ r4D66tF
sSiteURL = value; Jr''S}@|x
} ,\=u(Y\I[
0-|1}/{4
2lp.Td`{
public String getSFilePath() r<|\4zIo/
{ 3ZZJYf=
return sFilePath; v(: VUo]H
} c,D'Hl6(%
H}U&=w'
jNIM1_JjD
public void setSFilePath(String value) ]iz5VI@
{ J25>t^
sFilePath = value; UBU(@T(
} )bK<t
b-O4IDIT
/(}V!0\?
public String getSFileName() zJ9,iJyuD
{ W6_3f-4g
return sFileName; -%t0'cKn,
} Q z/pz_}
6iC}%eU
yRgo1ow]
public void setSFileName(String value) #%{\59/w
{ r?[mn^Bo5
sFileName = value; L>L4%?
} g{D&|qWj
,LMme}FFeb
+s S*EvF
public int getNSplitter() M"_XaVl
{ 5#fLGXP
return nSplitter; @DUdgPA
} M,#t7~t
tlcA\+%)
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public void setNSplitter(int nCount) QyN~Crwo
{ h:GOcLYM@X
nSplitter = nCount; .i. |wY
} wR4P0[
} BF_k~
IIu3mXAw
J%A`M\
/* (Dn-vY'
**Utility.java 5Px.G*
*/ ad~ qr n\
package NetFox; , m\0IgZdz
$}F]pa[
7<tqT @c
public class Utility { I;|Aiu*
P! 3$RO
CX:^]wY
public Utility() a-}%R
{ >3kR~:;
L.Lt9W2fi
tFSdi.|G=
} 7L\GI`y
*.+>ur?t
//线程睡眠 p/5!a~1'xN
public static void sleep(int nSecond) FlgB-qR]<n
{ 0Fw\iy1o
try{ /~^I]D
Thread.sleep(nSecond); 'wZy: c
} $Us@fJr
catch(Exception e) s7 KKH w
{ sogbD9Jc
e.printStackTrace (); @uE=)mP@
} }?~uAU-
} !Q3Snu=
RPX`2zr
//日志 6f>l~$
public static void log(String sMsg) v-gT 3kJ
{ ?% X9XH/!
System.err.println(sMsg); *~cs8<.!1
} FezW/+D
O1ha'@qID
bc4x"]!
public static void log(int sMsg) 4GfLS.Ip
{ 8(KfX%
System.err.println(sMsg); ]p*) PpIl
} )f!dG(\&#
} 48ma&f;
KVcZ@0[S
YJ^ lM\/<
/* &0eB@8{N
**TestMethod.java cMWO_$
*/ 5p|@)
package NetFox; }J?fJ(
XH *tChf<
QO7:iSZJ
public class TestMethod { 3uw7 J5x
^0|NmMJ]
cORMR!
public TestMethod() U>+~.|'V9
{ ///xx/weblogic60b2_win.exe mCt>s9a)H
try{ u,akEvH~a
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @Y<tH,*
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); z^/GTY
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]Z-oUO Z<k
fileFetch.start(); $ tNhwF
} "k<:a2R
catch(Exception e){e.printStackTrace ();} 1(i>Vt.+
6{$dFwl
bQy%$7UmX,
} fBgKX?Y
CdDd+h8
'^l^gW/|\
public static void main(String[] args) i f<<lq
{ -k <9v.:
new TestMethod(); y<1$^Y1/)
} Z&w^9;30P
} kNj3!u$
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