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)); WO=P~F<
} C ett*jm_
for(int i=0;i<nEndPos.length-1;i++) og`g]Z<I
{ T/P
nEndPos = nStartPos[i+1]; bA07zI2
} Da ]zbz%%
nEndPos[nEndPos.length-1] = nFileLength; A'suZpL
} /X;! F>
} 7ZFd;-
+,UuJ6[n
/ !aVv
//启动子线程 GpXU&A'r
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; zU";\);
for(int i=0;i<nStartPos.length;i++) :nS p
{ ~j[mME}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~|&To>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ]uXmug
nStartPos,nEndPos,i); @5{h+^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D 4<,YBvV
fileSplitterFetch.start(); }b+$S'`Bv
} ggUw4w/e
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :.crES7<[X
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); c>+hY5?C
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +T HBPEq
nEndPos = " + nFileLength); +kx#"L:
// fileSplitterFetch[nPos.length-1].start(); eKe[]/}e9
4okZ
%";ap8J04F
//等待子线程结束 +<'>~lDg
//int count = 0; hy"=)n(
//是否结束while循环 `gdk,L]
boolean breakWhile = false; v,c;dlg_
}i52MI1-XP
n!L}4Nmp
while(!bStop) @wh-.MD
{ 1 }_"2
write_nPos(); 9,$ n6t;
Utility.sleep(500); y-_IMu.J`
breakWhile = true; 4YA1~7R
!-tVt D
!=]cASPGD
for(int i=0;i<nStartPos.length;i++) CJt(c,!z
{ 6JD~G\$
if(!fileSplitterFetch.bDownOver) +K48c,gt?
{ BP=<TRp.
breakWhile = false; .2SD)<}(9
break; aPHNX)
} sM@1Qyv&0
} c.uD%
if(breakWhile) xd!GRJ<I
break; 7o9[cq w
m 3Do+!M[
ese?;1r
//count++; 1WAps#b.
//if(count>4) |fPR7-
// siteStop(); )OZ
} w%~Mg3|
-NUA
in2m/q?
System.err.println("文件下载结束！"); DYTC2
} bl[2VM7P
catch(Exception e){e.printStackTrace ();} ^F87gow%`B
} G`z=qaj
' [%?j?2r
( c +M"s
//获得文件长度 F+/#ugI
public long getFileSize() 4]no#lVRJ
{ *C,1x5
int nFileLength = -1; FLQ>,=O
try{ 4^k+wQU
URL url = new URL(siteInfoBean.getSSiteURL()); a>egH og
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )b-KF}]d
httpConnection.setRequestProperty("User-Agent","NetFox"); :</KgR0I
y~<_ux,
oEsqLh9a|
int responseCode=httpConnection.getResponseCode(); GE}>{x=^x
if(responseCode>=400) Z;cA_}5
{ RH"EO4
processErrorCode(responseCode); /;`-[
return -2; //-2 represent access is error QVe<Z A8N;
} ?, cI!c`
34t[]v|LD
h 2C9p2.
String sHeader; >Slu?{l'
YT<(2u#Ng
8xYeaK
for(int i=1;;i++) E]ZIm
{ ]?s^{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); g4GU28l
//Utility.log(in.readLine()); 6eW9+5oL
sHeader=httpConnection.getHeaderFieldKey(i); Z"E2ZSa0
if(sHeader!=null) [~k!wipK
{ C0;:")6~
if(sHeader.equals("Content-Length")) \+)AQ!E
{ x%55:8{
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); tF!-}{c"k
break; ZvSEa{
} FIpJ>E"n
} $aj:\A0f
else }PzHtA,V
break; 'Xg9MS&
} ,<fs+oi
} #<yKG\X?
catch(IOException e){e.printStackTrace ();} jNW/Biy4u
catch(Exception e){e.printStackTrace ();} TlJ'pG 4^
+kT o$_Wkz
7QHrb'c
Utility.log(nFileLength); o.])5i_HV
2Y%E.){
J pKCux
return nFileLength; L[lS >4eN
} ?]0bR]}y
}c'T]h\S
zX&wfE8T
//保存下载信息（文件指针位置） 8:jakOeT
private void write_nPos() bP{uZnOM2P
{ ~4M?[E&
try{ d*Kg_He-
output = new DataOutputStream(new FileOutputStream(tmpFile)); =p&uQ6.i+
output.writeInt(nStartPos.length); IvM>z03
for(int i=0;i<nStartPos.length;i++) !Z%pdqo`.
{ 47^7S=
// output.writeLong(nPos); >{=~''d,w
output.writeLong(fileSplitterFetch.nStartPos); P;ovPyoO
output.writeLong(fileSplitterFetch.nEndPos); DaqpveKa
} F,JqHa9
output.close(); t8t+wi!
} "^5%g%
catch(IOException e){e.printStackTrace ();} :tX,`G
catch(Exception e){e.printStackTrace ();} {\ J%i|u
} JmbWEX|
=7-@&S=?s
d.p%jVO)"
//读取保存的下载信息（文件指针位置） E~1"Nh
private void read_nPos() cB}6{c$_sW
{ H`NT`BE
try{ Vn6]h|vm
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !p(N DQm
int nCount = input.readInt(); Ky)*6QOw
nStartPos = new long[nCount]; ^zR*s |1Q
nEndPos = new long[nCount]; {Zf 9} !qF
for(int i=0;i<nStartPos.length;i++) _yc&'Wq
{ ?9;r|G
nStartPos = input.readLong(); A(wuRXnVWK
nEndPos = input.readLong(); !k8j8v&
} M[?0 ^ FBx
input.close(); dU#}Tk
} ,5P tB]8&3
catch(IOException e){e.printStackTrace ();} ^(1S`z$
catch(Exception e){e.printStackTrace ();} U$j?2|v-x
} B#[.c$
BS+=*3J
"ac$S9@~
private void processErrorCode(int nErrorCode) @fI2ZWN|
{ QP!0I01
System.err.println("Error Code : " + nErrorCode); E,7b=t
} cGS7s 8U
"i;"
a fUOIM
//停止文件下载 U )J/so)
public void siteStop() ^-26K|{3
{ /U@Y2$TOF
bStop = true; a<v!5\dq!
for(int i=0;i<nStartPos.length;i++) Wh1'?#
fileSplitterFetch.splitterStop(); iKEHwm
U].3vju`c
oPR?Ar
} SJ8|~,vL
} 1ika'
//负责部分文件的抓取 0-Vx!(
**FileSplitterFetch.java #\gx.2W7
*/ t? [8k&Z
package NetFox; GA2kg7
H]VoXJ\*
0Y9fK? (
import java.io.*; +cC$4t0$^A
import java.net.*; R9O1#s^
Un\ T} c
^_JByBD
public class FileSplitterFetch extends Thread { obSLy Ed
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/@+[D{_Fw
String sURL; //File URL tz/NR/[
long nStartPos; //File Snippet Start Position /%i:(Ny
long nEndPos; //File Snippet End Position h"On9
int nThreadID; //Thread's ID ')1p
boolean bDownOver = false; //Downing is over yo_;j@BGR
boolean bStop = false; //Stop identical mI-9=6T_
FileAccessI fileAccessI = null; //File Access interface n@y*~sG]
x4;ndck%U
YQ7tZl;:t
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >m8~Fs0
{ 0i/!nke.
this.sURL = sURL; D:Fi/JY~
this.nStartPos = nStart; \* SEj&9
this.nEndPos = nEnd; e6uVUzP4
nThreadID = id; FlepM*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )G@/E^ySM
} 70yM]C^
peGh-
;@V1*7y
public void run() g0A,VX:2
{ v}BXH4&Y
while(nStartPos < nEndPos && !bStop) 's 'H&sa
{ : 5<u!-}
Q'Vejz/
[.c'22R6
try{ AMc`qh
URL url = new URL(sURL); D~7L~Q]xI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +/DT#}JE
httpConnection.setRequestProperty("User-Agent","NetFox"); A!^gF~5
String sProperty = "bytes="+nStartPos+"-"; HR$;QHl~F
httpConnection.setRequestProperty("RANGE",sProperty); l$3YJ.n|s~
Utility.log(sProperty); Ygfv?
+~eybm;
#w&N) c>
InputStream input = httpConnection.getInputStream(); %S]g8O[}nl
//logResponseHead(httpConnection); wv&#lM(
q,*([yX
}WEF*4B!
byte[] b = new byte[1024]; 2*}qQ0J
int nRead; lbiMB~rwI
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) y(*#0fJrTV
{ fQ_(2+FM
nStartPos += fileAccessI.write(b,0,nRead); dIOiP\^
//if(nThreadID == 1) kyu PN<?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +z?SKc
} H:_R[u4r
c,_??8
to#N>VfD
Utility.log("Thread " + nThreadID + " is over!"); fE,Io3
bDownOver = true; 0=V -{
//nPos = fileAccessI.write (b,0,nRead); -1c{Jo
} <^fvTb&*
catch(Exception e){e.printStackTrace ();} I#9q^,,F
} *W$bhC'w
} NAh^2X
ZCz#B2Sf8
CCU<t Q
//打印回应的头信息 ;eT+Ly|{
public void logResponseHead(HttpURLConnection con) Or,W2
{ :XeRc"m<
for(int i=1;;i++) Tb<}GcwJ
{ w^8i!jCy
String header=con.getHeaderFieldKey(i); fe!{vrS
if(header!=null) ayh=@7*
//responseHeaders.put(header,httpConnection.getHeaderField(header)); vw[i.af
Utility.log(header+" : "+con.getHeaderField(header)); D=:O^<
else j/uu&\e
break; 2^4OaHY88
} )l[bu6bM
} Rxk0^d:sNi
i;mA|
H?tX^HO:q
public void splitterStop() l{4rKqtX
{ )k6kK}
bStop = true; 'O[0oi&
} m\e?'-(s
C5x*t Q|
^F:Bj&0v[
} x f<wM]&
sX,S]:X
!i5~>p|4@
/* MyaJhA6c
**FileAccess.java V3c7F4\
*//文件访问(定位，写) OS sYmF
package NetFox; DZqY=Sze
import java.io.*; vfloha p
pgEDh^[MW
MeW?z|x`'
public class FileAccessI implements Serializable{ u?I2|}#
l" +q&3Zx
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .T\_4C
RandomAccessFile oSavedFile; @23~)uiZa
long nPos; R/Z zmb{
f_'8l2jK1i
<#~n5W{l
public FileAccessI() throws IOException *^[j6
{ !8OgaMngzF
this("",0); }) Zcw1g
} zLybf:#
Zgt(zh_l
TeNPuY~WP
public FileAccessI(String sName,long nPos) throws IOException 17F<vo>l%
{ ")@#B=8+3^
oSavedFile = new RandomAccessFile(sName,"rw"); ch]{=61
this.nPos = nPos; jH?!\F2)+
oSavedFile.seek(nPos); ED^0t
} aDda&RM
uS7kkzt-x
:s>x~t8g#n
public synchronized int write(byte[] b,int nStart,int nLen) C@{-$z)
{ IQeiT[TF
int n = -1; y7| 3]>Z
try{ S pk8u4
oSavedFile.write(b,nStart,nLen); '^%kTNn
n = nLen; ,)ZI&BL5
} r1/9BTPKdJ
catch(IOException e) JsHD3
{ hO; XJyv
e.printStackTrace (); &gsBbQ+qA
} p> g[: ~
vW4n>h}]
AL;4-(KH
return n; I`;SA~5
} ^MO})C
}56WAP}Z 4
>)+N$EN
} _BZ6Ws$C2
xQkvK=~$
a!B"WNb+
/* CN:z *g
**SiteInfoBean.java ;@xlrj+
*/ '8=/v*j>?
package NetFox; :*Y2na)qQ
+ f,Kt9Cy
kxmc2RH>nB
public class SiteInfoBean { "/Pq/\,R|
"{[\VsX|c
gUY~ l= c
private String sSiteURL; //Site's URL u6SQq-)d
private String sFilePath; //Saved File's Path L}6!D zl
private String sFileName; //Saved File's Name 9qUkw&}H
private int nSplitter; //Count of Splited Downloading File mM.YZUX
Ug\$Ob5=q
XIn,nCY;
public SiteInfoBean() %Ni"*\
{//nSplitter的缺省值为5 5GbC}y>
//default value of nSplitter is 5 xJ9aFpTC
this("","","",5); LkXho>y
} ><I{R|bC
lBGYZ--
)6(|A$~C+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 3,-[lG@o
{ >:HmIW0PLe
sSiteURL= sURL; [Qcht,\^v
sFilePath = sPath; Z@}qL1
sFileName = sName; rFaG-R
this.nSplitter = nSpiltter; ty'/i!/\
2'u%
fZrh_^yH
} LGK@taw^
_!,Ees=b
^h^.;Iqr=
public String getSSiteURL() in6*3C4
{ (eSsx/
return sSiteURL; ")<5VtV
} 54=*vokX_
aa"3 Io
GSW%~9WBa
public void setSSiteURL(String value) pQ>|dH+.
{ OX%#8Lx
sSiteURL = value; U7Oa 13Qz
} 2T(7V[C%9
fbD,\ rjT
cQ |Q-S
public String getSFilePath() 4AMe>s
{ UE/JV_/S;
return sFilePath; `aTw!QBfG
} PQp/&D4K
0TZB}c#qT
sUU[QP-
public void setSFilePath(String value) .N( X.C
{ `]^W#6l
sFilePath = value; n'0r (
} > l]Ble
Ft?eqDS1
V>/,&~0
public String getSFileName() vn!5@""T
{ hQ'W7EF
return sFileName; YmOj.Q&
} ea]qX6)UZ
%z=:P{0UQ
ja9=b?]0,
public void setSFileName(String value) Wf^sl
{ ?U+hse3e~
sFileName = value; <ZheWl
} hz*T"HJ]t
lv9Tq5C
+(PUiiP'"v
public int getNSplitter() *ow`}Q
{ XwFTAaZ
return nSplitter; .]s? 01Z
} >]8(3&zd
s1h|/7gG
RMiDV^.u`
public void setNSplitter(int nCount) UI"UBZZ$
{ `S0`3q}L3%
nSplitter = nCount; _QEw=*.<
} ;|0P\3
} >I/@GX/
;!G#Y Oe
6aOyI;Ux
/* /QWXEL/M=
**Utility.java Y[]I!Bc
*/ :)i,K>y3i
package NetFox; NU3TXO
`hdff0
1YQYZ^11
public class Utility { AwjXY,2
ZuybjV1/f6
[NAfy~X*
public Utility() rZ|p{ym
{ ]E$NJq|
[T,Hpt
2x9.>nwhb
} W=3#oX.GsU
#4./>}G
//线程睡眠 , ^K.J29
public static void sleep(int nSecond) c?e-2Dp(
{ YoW)]n
try{ S3l^h4
Thread.sleep(nSecond); wU>Fz*
} /,\U*'-
catch(Exception e) QS!Z*vG
{ yQMwt|C4
e.printStackTrace (); Zp^O1&\SK?
} )obgEJ7Y`l
} H`'a|Y
w7.,ch
//日志 1Acs0`3
public static void log(String sMsg) ?'Hd0)yZ
{ LWm1j:0
System.err.println(sMsg); 1O<6=oH
} g4b#U\D@)/
IdN3Ea]
/ Ws>;0
public static void log(int sMsg) Sc/l.]k+
{ u*): D~A
System.err.println(sMsg); }6!/Nb
} kl]MP}wc
} h x&"fe
|T@SlNi]
,}&TZkN{-
/* YI ?P@y
**TestMethod.java `BKb60
*/ Er%&y
package NetFox; r'j88)^
2H}y1bkW
Vj9X6u}{
public class TestMethod { \cCH/
(;;ji!i
;b*qunJ3L
public TestMethod() fs 2MYat
{ ///xx/weblogic60b2_win.exe l=p_
try{ 5{k,/Z[L
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); KD,3U/3
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); # :k=
SiteFileFetch fileFetch = new SiteFileFetch(bean); _%=CW' B
fileFetch.start(); 3a.!9R>
} \? )S{
catch(Exception e){e.printStackTrace ();} erW2>^My
V~[b`&F
]sqLGmUL
} 4r7F8*z
rAfz?
u+r!;-0i
public static void main(String[] args) babL.Ua8o
{ :\P@c(c{^C
new TestMethod(); l;0([_>*j
} CTW\Dt5
} i7-~"g
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