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)); *Ue#Sade
} }9;mtMR$
for(int i=0;i<nEndPos.length-1;i++) CteNJBm
{ .0;\cv4}
nEndPos = nStartPos[i+1]; :QXKG8^
} 7+hc?H[&'
nEndPos[nEndPos.length-1] = nFileLength; ua_,c\iL
} W%o! m,zFM
} ^<
*Gj`1#Z$
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//启动子线程 1Y~'U =9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8|5+\1!#/)
for(int i=0;i<nStartPos.length;i++) 6Lg#co}9
{ 3 +`,'Q9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fRkx ^u P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6k<3,`VV|
nStartPos,nEndPos,i); ~d ~oC$=TC
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B7oUS}M
fileSplitterFetch.start(); 2=1qmQE
} kqq1;Kd
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s;]"LD@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); gi)C5J4
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", :7(d6gEL
nEndPos = " + nFileLength); /ZH*t\
// fileSplitterFetch[nPos.length-1].start(); wub7w#
JRAU|gr
Lc "{ePFh
//等待子线程结束 L6ypn)l
//int count = 0; "1%k"+&
//是否结束while循环 ?`6Mfpvj96
boolean breakWhile = false; cHVu6I?h
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T| R!Aw.
while(!bStop) z=8l@&hYLq
{ K 6,c||#<
write_nPos(); ]"j%:fr
Utility.sleep(500); .G"T;w6d
breakWhile = true; `R lWhdE
-B-HZ_
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for(int i=0;i<nStartPos.length;i++) fWF!%|L
{ qQ,(O5$|
if(!fileSplitterFetch.bDownOver) KxfH6:\RB
{ r]wy-GT
breakWhile = false; t_(Se
break; NL!xkcXO
} s9fEx-!y
} I+jc
if(breakWhile) yWr&G@>G
break; A-$C6q
'kg~#cf/+
WM=)K1p0u
//count++; $d&7q5[
//if(count>4) 2o W'B^-
// siteStop(); DLe>EU;vS
} 2&AX_#P
~i>'3j0@k
^nQJo"g\
System.err.println("文件下载结束！"); )]m4FC:
} #ZHKq7
catch(Exception e){e.printStackTrace ();} 7&L8zl|K
} )[yKO
6QPT
@]EdUzzKq
//获得文件长度 -:b<~S[
public long getFileSize() \Z~ <jv
{ {WeRFiQ?-
int nFileLength = -1; hIa,PZ/Q
try{ ?b(DDQMf
URL url = new URL(siteInfoBean.getSSiteURL()); I6S>*V
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &@PAv5iNf
httpConnection.setRequestProperty("User-Agent","NetFox"); l[nf"'
a"k,x-EL(
:U @L$
int responseCode=httpConnection.getResponseCode(); e >7Ka\
if(responseCode>=400) M?['HoRo
{ @Qqf4h
processErrorCode(responseCode); cn9=wm\\
return -2; //-2 represent access is error CKU)wJ5t
} }UG<_bE|
D{4]c)>
ItAC=/(d
String sHeader; GzT?I 7|M
&kH7_Lz
X{h[
for(int i=1;;i++) V:gXP1P
{ KF`mOSP
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~6OdwGWV
//Utility.log(in.readLine()); (W9 K:]}
sHeader=httpConnection.getHeaderFieldKey(i); =]<X6!0mR
if(sHeader!=null) P>|sCF
{ .e5rKkkT
if(sHeader.equals("Content-Length")) ,JJ1sf2A
{ Jd33QL}Hj
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :1#$p
break; !B#tJD
} g{m~TVm'
} Z>W&vDeuN
else xQqZi b5I
break; VB4ir\nF
} xp"F)6
} !Jaj2mS.N
catch(IOException e){e.printStackTrace ();} w4UJXc
catch(Exception e){e.printStackTrace ();} :&s8G*
!1bATO:x
pEb/yIT"
Utility.log(nFileLength); 1EliR uJ
3gW+|3E
zR}vR9Ls
return nFileLength; jZqCM{
} asYUb&Hz88
~A*$+c(
\Iz-<:gA'
//保存下载信息（文件指针位置） 8oJp_sw
private void write_nPos() (i]0IYMXy*
{ ,k,+UisG
try{ ,WS{O6O7
output = new DataOutputStream(new FileOutputStream(tmpFile)); k| >zauK
output.writeInt(nStartPos.length); ^O3p:X4u
for(int i=0;i<nStartPos.length;i++) ,.uI>
{ :U'Oc3l#Y
// output.writeLong(nPos); S$nEflcz
output.writeLong(fileSplitterFetch.nStartPos); ^=w){]G
output.writeLong(fileSplitterFetch.nEndPos); sfCU"O2G
} ER<Z!*2
output.close(); #:[CF:
} =o4McV}
catch(IOException e){e.printStackTrace ();} q&: t$tSS
catch(Exception e){e.printStackTrace ();} C)ebZ3
} XC[bEp$
8?t}S2n2
?#u_x4==e
//读取保存的下载信息（文件指针位置） PE2O$:b\
private void read_nPos() =UZm4=T
{ `q?@ Ob&
try{ x)e(g}n
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); JE[J}-2
int nCount = input.readInt(); t~ z;G%a
nStartPos = new long[nCount]; fZ pUnc
nEndPos = new long[nCount]; +Pb@@C&
for(int i=0;i<nStartPos.length;i++) Yr 1k\q
{ /m+.5Qz9)@
nStartPos = input.readLong(); *En4~;l
nEndPos = input.readLong(); $Q56~AP
} Qy|6A@
input.close(); }j|YX&`p
} Zex`n:Wl?j
catch(IOException e){e.printStackTrace ();} ROr| <
catch(Exception e){e.printStackTrace ();} \Oa11c`6
} qUG)+~g`
3aEO9v,n
=~{W;VZt'
private void processErrorCode(int nErrorCode) a*Ng+~5)6
{ -!:h]
System.err.println("Error Code : " + nErrorCode); MF4B 2d
} :.W</o~\s
jg=}l1M"
X6EnC57
//停止文件下载 p(S {k]ZL@
public void siteStop() WlnS.P\+E
{ j79$/ Ol
bStop = true; =42NQ{%@;
for(int i=0;i<nStartPos.length;i++) QhmOO-Z?
fileSplitterFetch.splitterStop(); bODyJ7=[
,IQ%7*f;O_
')~[J$qz
} 5*r5?ne
} (Ei} :6,}
//负责部分文件的抓取 jI,?*n<
**FileSplitterFetch.java 3+WostOx
*/ p"=8{LrO
package NetFox; S+//g+e|f
9c=`Q5
gYvT'72
import java.io.*; <'z.3@D
import java.net.*; _}:#T8h
bn0Rv
eLN[`hJ
public class FileSplitterFetch extends Thread { g9:V00^<
!jyy`q=
6eAJ>9@x
String sURL; //File URL 5D`!Tu3
long nStartPos; //File Snippet Start Position td\'BV
long nEndPos; //File Snippet End Position 55vI^SSA
int nThreadID; //Thread's ID :A]CD(
boolean bDownOver = false; //Downing is over h&:6S
boolean bStop = false; //Stop identical *aS[^iX?s
FileAccessI fileAccessI = null; //File Access interface g2W ZW#a)
L$ ZZ]?7j
38gEto#q
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =1Tn~)^O
{ ;@G5s+<l
this.sURL = sURL; }R2afTn[;
this.nStartPos = nStart; v!%VH?cA8
this.nEndPos = nEnd; m0+'BC{$u
nThreadID = id; @[w.!GW%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 VfJdCg_
} [rtMx8T
{.D/MdwW;
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public void run() WS1$cAD2N
{ PBp+(o-
while(nStartPos < nEndPos && !bStop) ]:F?k#c
{ #FsoK*F
p)w{}@%r
^DOQ+
try{ 5qQ\H}
URL url = new URL(sURL); Ur2)];WZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -<M'h
httpConnection.setRequestProperty("User-Agent","NetFox"); #wP$LKk
String sProperty = "bytes="+nStartPos+"-"; gaxxB]8
httpConnection.setRequestProperty("RANGE",sProperty); P~7p~ke
Utility.log(sProperty); >`u/#mrd
:}p<Hq 8Z
X UcM~U-
InputStream input = httpConnection.getInputStream(); Jw)-6WJ!uO
//logResponseHead(httpConnection); g"Gj8QLDz
p-,(P+Np
%8~g#Z
byte[] b = new byte[1024]; P_Ni 5s)
int nRead; &(YNz9L
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) V[baGNe
{ V{yk
nStartPos += fileAccessI.write(b,0,nRead); u<K{=94!e
//if(nThreadID == 1) fT
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +DA,|~k_
} ( t59SY
f~Q]"I8w
a7wc>@9Q,
Utility.log("Thread " + nThreadID + " is over!"); A,#a?O6m
bDownOver = true; +EE(d/f
//nPos = fileAccessI.write (b,0,nRead); <A@qN95m
} _&|<(m&."
catch(Exception e){e.printStackTrace ();} C!s !j
} *ci%c^}V
} }D7} %P]
o`<ps$yT
`sPH7^R
//打印回应的头信息 ;Br #e1~
public void logResponseHead(HttpURLConnection con) !;h`J:dN
{ \1mTKw)S
for(int i=1;;i++) z]bcg$m
{ z`KP }-
String header=con.getHeaderFieldKey(i); yy#4DYht
if(header!=null) %m?$"<q_K
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Zia<$kAO
Utility.log(header+" : "+con.getHeaderField(header)); \:|"qk
else o0\d`0-el
break; n>aH7
} Ch,%xs.)G
} lz88//@gZ
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kcyT#'=j
public void splitterStop() `d6,]'
{ 6qH^&O][
bStop = true; ~ w,hJ `
} 9G=HG={
5BsfbLKC
hR(p{$-T
} Mv#\+|p 1x
g&`[r6B
(Q~(t
/* 6Z7J<0
**FileAccess.java ; 6*Ag#Z
*//文件访问(定位，写) kRH;c,E@
package NetFox; `R{ ZED l'
import java.io.*; [>wvVv
z1`z k0
to"[r
public class FileAccessI implements Serializable{ $mZpX:7/u8
#uHl
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @!:_r5R~N
RandomAccessFile oSavedFile; \jGvom.
long nPos; @#W$7Gwf0
PP_fTacX
1?N$I}?
public FileAccessI() throws IOException ;$>wuc'L
{ gg}^@h&?
this("",0); yNkE>
} O| zLD
>HlQ+bl$xw
`p{,C`g,R
public FileAccessI(String sName,long nPos) throws IOException <;.->73E
{ @!zT+W&
oSavedFile = new RandomAccessFile(sName,"rw"); HG)c\b
this.nPos = nPos; 4bZ +nQgLu
oSavedFile.seek(nPos); I'%(f@u~
} ` "JslpN
0&k!=gj:>Z
9}DF*np`G
public synchronized int write(byte[] b,int nStart,int nLen) Yt% E,U~g
{ 4hh=z>$|l)
int n = -1; Wy.Xx-3W
try{ YMEI J}
oSavedFile.write(b,nStart,nLen); j*05!j<'
n = nLen; Wr+1G 8
} |~I-
catch(IOException e) |#D$9+
{ YDMimis\H5
e.printStackTrace (); 5{uK;Vxse
} gQ=g,X4
"TgE@bC
:5M7*s)e16
return n; I N'a5&..
} &^W91C?<6
t%f6P
]{<`W5b/
} /kY|PY
)|@ H#kv?
CL-mt5Kx#7
/* \%!~pfM I
**SiteInfoBean.java CrIt h/Z
*/ )KLsa`RV:
package NetFox; +s'qcC
utvZ<zz`
uM^eoh_
public class SiteInfoBean { KiJRq>
Pkbx/\
F9Ag687w
private String sSiteURL; //Site's URL $`emP Hel
private String sFilePath; //Saved File's Path z$>_c"D
private String sFileName; //Saved File's Name -K_p? l
private int nSplitter; //Count of Splited Downloading File H-sJt:
p(F}[bP
|GvWHe`
public SiteInfoBean() '$3]U5KOwK
{//nSplitter的缺省值为5 >*PZ&"}M
//default value of nSplitter is 5 ByrK|lVM0
this("","","",5); 9aR-kcvJIJ
} OeuM9c{
@k!J}O K
$EB&]t+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }T?0/N3y&
{ <J`",h
sSiteURL= sURL; G 1rsd
sFilePath = sPath; #S/]=D
sFileName = sName; )Qe4J0.
this.nSplitter = nSpiltter; cViEvS r
mZ^z%+Ca|
H+`s#'(i_P
} zoV4Gl
"eq{_4dL
Zz<k^
public String getSSiteURL() fWx %?J
{ 37hs/=x
return sSiteURL; K85;7R5
} (cX;a/BR
4LRrrW
8,Jjv*
public void setSSiteURL(String value) J6eF7 fa
{ j~(s3pSCo
sSiteURL = value; L> ehL(]!
} cnQ;6LtFTz
hjVct r
'~HCYE:5
public String getSFilePath() G x;U 3iV
{ >+iJ(jqq
return sFilePath; B? $9M9
} [Bn C_^[W
&@tD/Jw3
4l/hh|3@
public void setSFilePath(String value) Yv?nw-HM
{ >wz&{9ni
sFilePath = value; 5OUGln5
} xV&c)l>}
'Vwsbm tY
A>@ i TI
public String getSFileName() +gZg7]!Z
{ .+|HJ(
return sFileName; dWK; h
} \qx$h!<
)-D{]>8
&cnciEw1
public void setSFileName(String value) snPM&
{ Tm!pAD
sFileName = value; ,$i2vGd
} Y>Oh]?
x*]&Ca0+
ZY_aE
public int getNSplitter() }HO3D.HE^
{ $AGW8"
return nSplitter; ;WydXQ}Q^
} HPz9Er
)qDCh
*P\$<4l
public void setNSplitter(int nCount) mGss9eZa
{ ]q#w97BxiJ
nSplitter = nCount; #~3$4j2U(y
} :%_*C09
} RKIBFP8.
3X&'hz@
(T290a9y>
/* GyirE`
**Utility.java .b.pyVk
*/ (R'GrN>
package NetFox; I&2)@Zw
79m',9{u
K1S:P( S
public class Utility { NOC8h\s}(
p"%K(NL
caG5S#8-"
public Utility() , %8keGhl
{ o|Q:am'H
eo#2n8I>=1
2p^Jqp`$
} 9i6z p'
|M8FMH[_
//线程睡眠 ":qhO0
public static void sleep(int nSecond) D^_]x51>
{ 9Dat oi
try{ -0I]Sm;$
Thread.sleep(nSecond); M%yeI{m
} 5L?_AUL
catch(Exception e) =,MX%-2
{ hFW{qWP
e.printStackTrace (); `6No6.\J
} ",v!geMvu
} A$JL"~R
*#n#J[
//日志 +hIC N,8!
public static void log(String sMsg) 7>-"r*W +z
{ E;o "^[we
System.err.println(sMsg); -XJXl}M.
} ~ERA
*GZ7S m
Kggc9^ 7
public static void log(int sMsg) r(ZMZ^
{ pdw;SIoC
System.err.println(sMsg); h,*-V 'X.k
} c,yjsxETW
} dED&-e#
hZwbYvu
J<vVsz+7:
/* ML!>tCT
**TestMethod.java srGF=1_
*/ V*I2
package NetFox; d71|(`&
*SmR|Qy
K ; eR)
public class TestMethod { Puq
Zk+c9,q
N51e.;
public TestMethod() 9F"^MzZ
{ ///xx/weblogic60b2_win.exe SZVAf|]Yg
try{ KsDovy<
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); J=?P`\h
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); VprrklZ
SiteFileFetch fileFetch = new SiteFileFetch(bean); '89nyx&W
fileFetch.start(); >Tp`Kri
} eJy}W /
catch(Exception e){e.printStackTrace ();} ra|Ku!
&~&oB;uR
&Cm$%3
} e6i m_ Tk
hQ80R B
?'^dYQ4
public static void main(String[] args) d "%6S*dL
{ Yl`)%6'5|
new TestMethod(); w{"ro~9o
} M`49ydh&
} .L8g(F(=:
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