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)); |+!Jr_ By
} X?>S24I"9
for(int i=0;i<nEndPos.length-1;i++) tjDVU7um
{ ed{z^!w4
nEndPos = nStartPos[i+1]; l-t:7`=|
} YvBUx#\
nEndPos[nEndPos.length-1] = nFileLength; 1(q!.lPc
} ;a{ Dr
} C9gF2ii|?
)KXLL;]
+]uy
//启动子线程 bGK&W;Myk
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; T%P0M*
for(int i=0;i<nStartPos.length;i++) J4`08,
{ 5uDQ*nJ|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S`0@fieOf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), jq.@<<j|$
nStartPos,nEndPos,i); ,e.y4 vnU
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7:x.08
fileSplitterFetch.start(); ~p'/Z@Atu
} 'QCvN b6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~JC``&6E=}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); yaR|d3ef?4
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ik&loM_
nEndPos = " + nFileLength); ,Oxdqxu7
// fileSplitterFetch[nPos.length-1].start(); {y<_S]0
~e%*hZNo
"ajZ&{Z
//等待子线程结束 pNQd\nY|0
//int count = 0; ),M8W15
//是否结束while循环 d:A+s>`$M
boolean breakWhile = false; Lb2Bu>
NNe'5q9
guwnYS
while(!bStop) }E?s*iP
{ %A82{
write_nPos(); xFg=Tyq:
Utility.sleep(500); L?al2aopF
breakWhile = true; ~0/=5 dC
ld9zOq
.YS[Md{
for(int i=0;i<nStartPos.length;i++) LgBs<2
{ rzqCQZHL5
if(!fileSplitterFetch.bDownOver) vja^O
{ CZ]+B8Pl(x
breakWhile = false; L0+@{GP?
break; +pf 7
} .Z/"L@
} Nkv2?o>l
if(breakWhile) A\4Gq
break; )}paQmy#
>Pv%E
6 _73
//count++; ^GRd;v=-@
//if(count>4) UK_2i(I"e
// siteStop(); @Chj0wWZ>
} YjHGdacs
-$e\m] }Z
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System.err.println("文件下载结束！"); It]CoAo+
} ]&}?J:+?0E
catch(Exception e){e.printStackTrace ();} <Xl G:nmY
} YciZU
\;P Bx &
o<C~67o_
//获得文件长度 ]t#,{%h
public long getFileSize() ](T*f'LN
{ 2H]&3kM3X
int nFileLength = -1; B623B HwS
try{ &<!I]:Y
URL url = new URL(siteInfoBean.getSSiteURL()); >TL0hBaaR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VaQ}XM
httpConnection.setRequestProperty("User-Agent","NetFox"); ?dxhe7m
}]g>PY
?+5K2Zk
int responseCode=httpConnection.getResponseCode(); ~hM4({/QN
if(responseCode>=400) c-s ~q/
{ 8dL(cC
processErrorCode(responseCode); A1YIPrav(
return -2; //-2 represent access is error E; RI.6y
} +j`*?pPD(.
A>d*<#x
eRv3ZHH
String sHeader; s\kkD*
RQe#X6'h
t%8*$"~X
for(int i=1;;i++) N'[^n,\(:
{ `D?vmSQ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (a)d7y.oo
//Utility.log(in.readLine()); kyY tL_SD
sHeader=httpConnection.getHeaderFieldKey(i); RYvS,hf6z
if(sHeader!=null) 4;&(
{ /B1NcRS
if(sHeader.equals("Content-Length")) r--"JO%2
{ \&W~nYXq"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); RJd55+h
break; [kC-g @
} BJ{mX>I(
} N %0F[sY6
else 8G{} r
break; \W*ouH
} (c[|k
} ,T1t`
catch(IOException e){e.printStackTrace ();} eqjl$QWPJS
catch(Exception e){e.printStackTrace ();} r!#a.
9nd'"$
z?E:s.4F
Utility.log(nFileLength); UHR)]5Lt
v)X1R/z5xw
!@*Ac$J>$
return nFileLength; ]LP&v3
} QF\NHV
v}[7)oj|
ot,<iE#za
//保存下载信息（文件指针位置） nP_s+k
private void write_nPos() G]5'U"cj3
{ U24?+/5D]
try{ xT=|Uc0
output = new DataOutputStream(new FileOutputStream(tmpFile)); %JiA,
output.writeInt(nStartPos.length); Vl'|l)b4W
for(int i=0;i<nStartPos.length;i++) BBy/bc!
{ B23R9.FK
// output.writeLong(nPos); lm@<i4%$F
output.writeLong(fileSplitterFetch.nStartPos); ^#"!uCq]gM
output.writeLong(fileSplitterFetch.nEndPos); oOJN?97!k
} yNI}=Z
output.close(); rY($+O@a<
} %iF< px?Vc
catch(IOException e){e.printStackTrace ();} ^WM)UZEBC
catch(Exception e){e.printStackTrace ();} %]
} 8tPq5i
LI(Wu6*Y
Yo:>m*31
//读取保存的下载信息（文件指针位置） uZW1 :cx
private void read_nPos() H\)on"
{ Ym0Xl(Se
try{ Oja)J-QXb
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2:2rwH }e
int nCount = input.readInt(); ;XGG&M%3
nStartPos = new long[nCount]; Y_f6y9?ZE
nEndPos = new long[nCount]; ^$yr-p%-
for(int i=0;i<nStartPos.length;i++) [l'~>
{ CXJ0N
nStartPos = input.readLong(); })ss.
nEndPos = input.readLong(); J}<k`af
} .cle^P
input.close(); 5H?`a7q N
} Q0nSOTQ
catch(IOException e){e.printStackTrace ();} gxL5%:@
catch(Exception e){e.printStackTrace ();} HiVF<tN
} |\Qr cf
n_?<q{GW
Po=)jkW
private void processErrorCode(int nErrorCode) 0y|}}92:
{ uKtrG,/ p
System.err.println("Error Code : " + nErrorCode); 875V{fvPBU
} qTiX;e\W
f@>27&'WV
8[}MXMRdb
//停止文件下载 EDkxRfY2/
public void siteStop() QxjX:O
{ 9*lkx#
bStop = true; 5_}e?T&s
for(int i=0;i<nStartPos.length;i++) 1; "t8.*%e
fileSplitterFetch.splitterStop(); +#|):aF
v1E=P7}\{s
djxM/"xo
} |0jmOcZF
} !^/Mn
//负责部分文件的抓取 ZX Sl+k.
**FileSplitterFetch.java E*F)jP,yo
*/ ^ew<|J2,B
package NetFox; =:;KYuTr
xn)eb#r
l`}Ag8Q
import java.io.*; <\If:
import java.net.*; Wveba)"$
dT9ekNQB
1>!wm0;x
public class FileSplitterFetch extends Thread { v-J9N(y"
;Q0WCm\5
yQXHEB
String sURL; //File URL ^ld?v
long nStartPos; //File Snippet Start Position VZJ[h{ 6
long nEndPos; //File Snippet End Position ^S'#)H-8C3
int nThreadID; //Thread's ID Rt{`v<
boolean bDownOver = false; //Downing is over W?B(Jsv
boolean bStop = false; //Stop identical BIr24N
FileAccessI fileAccessI = null; //File Access interface K[XFJ9
=`l).GnN2`
{_]'EK/w
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5"]t{-PD
{ jr9/
this.sURL = sURL; y+PiH
this.nStartPos = nStart; -a}d @&
this.nEndPos = nEnd; dK45&JHoW^
nThreadID = id; HcrI3v|6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]-D;t~
} 1;4] HNI
#''q :^EQ
rU{E}
public void run() bS9<LQ*
{ 0K&\5xXM
while(nStartPos < nEndPos && !bStop) Viu+#J;l
{ v.ftfL!
,;2x.We
J"x M[c2
try{ ( _{\tgSm
URL url = new URL(sURL); r95l.v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2eOde(K+
httpConnection.setRequestProperty("User-Agent","NetFox"); Pc*+QtQ
String sProperty = "bytes="+nStartPos+"-"; bLfbzkNV\1
httpConnection.setRequestProperty("RANGE",sProperty); Z{|U!tn
Utility.log(sProperty); XU}|Ud562
`Xbk2KD p
$:YJ<HvG<
InputStream input = httpConnection.getInputStream(); y'9 bs
//logResponseHead(httpConnection); f8DF>]WW
RtR5ij1
3xJ_%AD\'
byte[] b = new byte[1024]; ~\9bh6%R
int nRead; S&C
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) l&z)Q/>?pZ
{ gGiLw5o,
nStartPos += fileAccessI.write(b,0,nRead); r# }`{C;+5
//if(nThreadID == 1) nj7wc9z4
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z'G~b[kG4n
} ^}-(8~_en
6tE<`"P!
=/k*w#j
Utility.log("Thread " + nThreadID + " is over!"); O!b >
bDownOver = true; COx<X\
//nPos = fileAccessI.write (b,0,nRead); `dYM+ jpa
} -1Luyuy/`
catch(Exception e){e.printStackTrace ();} 39W6"^q"o
} 6E!CxXUX
} Q&Rj)1!
}<EA)se"
s^/<6kwO
//打印回应的头信息 y<G@7?
public void logResponseHead(HttpURLConnection con) EcA@bZ0
{ ?w}E/(r
for(int i=1;;i++) $?l?
{ sW":~=H
String header=con.getHeaderFieldKey(i); O MEPF2:
if(header!=null) H-Uy~Ry*T
//responseHeaders.put(header,httpConnection.getHeaderField(header)); WH.5vrY Z
Utility.log(header+" : "+con.getHeaderField(header)); #!?5^O
else |/?)u$U<
break; >qJRpO
} !cs+tm3
} m,e@bJ-
*{]9e\DF
p7"o:YSQ
public void splitterStop() qp-/S^%
{ #-9;Hn4x
bStop = true; ,3k"J4|d
} 8 0>qqz
e,_b
hCX}*
} #L-3eW=f
rNL*(PN}lO
{]\QUXH
/* =TDK$Ek
**FileAccess.java BfLh%XC
*//文件访问(定位，写) I9ga8mG4-'
package NetFox; +"!,rZ7,A
import java.io.*; _5^p+
6#+&_#9
Rx$5#K!%M
public class FileAccessI implements Serializable{ ,zy4+GW
xzFV]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 a.a5qwG
RandomAccessFile oSavedFile; ~M 6^%
long nPos; Q"UQv<
c~0YIk>]
:^DuB_
public FileAccessI() throws IOException ellj/u61bj
{ V4GcW|P4y
this("",0); T jO}P\p
} s4 o-*1R*`
bJD2c\qoc
TxYxB1C)
public FileAccessI(String sName,long nPos) throws IOException VJMn5v[V
{ EPCu
oSavedFile = new RandomAccessFile(sName,"rw"); Gw6*0&3')
this.nPos = nPos; u4L&8@
oSavedFile.seek(nPos); (]Z%&>*
} `z$<1QT
J9^RP~>bs
tI&Z!fj
public synchronized int write(byte[] b,int nStart,int nLen) hlxZq
{ y< hIXC
int n = -1; zrjqB3R4@O
try{ !<3(+H
oSavedFile.write(b,nStart,nLen); NZ`( d
n = nLen; d%Zt]1$
} 7d?'~}j
catch(IOException e) #/ 1
{ 5taYm'
e.printStackTrace (); pHlw&8(f"
} Nhv~f0
7p&%0'BO1z
H4 }^6><V
return n; Ij hC@5qk
} DCv~^
3&kHAXzM
y; Up@.IG
} QDS=M]
6R1){,8
B98&JoS
/* g]9!Pi8jn
**SiteInfoBean.java d#.9!m~.
*/ Vkdchc
package NetFox; i~}[/^
qG=9zp4y?Y
xI}h{AF7
public class SiteInfoBean { n%I%O7
i{w<4E3
KTd,^h
private String sSiteURL; //Site's URL yZbO{PMr
private String sFilePath; //Saved File's Path <U=:N~L
private String sFileName; //Saved File's Name N=&~3k
private int nSplitter; //Count of Splited Downloading File Dh0`t@
az~4sx$+}
XM$r,}B k
public SiteInfoBean() k41lw^Jh
{//nSplitter的缺省值为5 UUy|/z%
//default value of nSplitter is 5 }3cOZd_,t
this("","","",5); _"%ef"oPh
} yw`xK2(C$
&Ib8xwb:
0"$Ui#r`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Q>u$tLX&
{ "q4c[dna
sSiteURL= sURL; r#wMd9])
sFilePath = sPath; ? &ew$%
sFileName = sName; 5_b`QO
this.nSplitter = nSpiltter; zJS,f5L6)
E~xK1x"
HONrt|c
} -crKBy
w `6qT3v
ZKyK#\v<
public String getSSiteURL() y\b.0-z
{ QIVpO /@
return sSiteURL; Fn*clx<
} l?v-9l M
#*;(%\q}
NvWwj%6]
public void setSSiteURL(String value) 306C_M\$
{ |*"uj
sSiteURL = value; u1O?`
} E~]8>U?V
^HumyDD6
P&C,EE$
public String getSFilePath() E^_P
{ x]lv:m\)jT
return sFilePath; w1EYXe
} S P)$K=
=1fO"|L
S/& _
public void setSFilePath(String value) 0f/=C9L
{ ,/{mRw%
sFilePath = value; a?K=
} )s(J8J[b*L
,Khhu%$
D+d\<":
public String getSFileName() y% =nhV
{ nY"9"R\.=
return sFileName; @47MJzC
} w}^z1n
$+)2CXQe5
;|e{J$
public void setSFileName(String value) qYc]Y9fi
{ 72@raA#y
sFileName = value; l~Je]Qt
} FqAW><
d9h"Q
-8; ,#
public int getNSplitter() 1tU}}l
{ *_}|EuY
return nSplitter; Fyoy)y*
} gE]) z*tqX
tpj({
x;89lHy@e
public void setNSplitter(int nCount) o&)O&bNJ
{ {;]:}nA
nSplitter = nCount; Q[`J=
} /~V.qisZ
} DesvnV'{`
%m1k^
c%c/mata?
/* (-DA%
**Utility.java (nfra,'
*/ \9dSI
package NetFox; +J30OT8
}2-<}m9}
O= PFr"
public class Utility { #+p30?r0y
Lzu;"#pw
|BhfW O8p
public Utility() YG$2ySkDhE
{ Z W` Ur>
VQV7W
EL$"MT}p
} saQA:W;
p"f=[awp
//线程睡眠 -q\5)nY
public static void sleep(int nSecond) 4Waot
{ ^:W.R7|
try{ N r5 aU6]
Thread.sleep(nSecond); eYBo*
} =(b;Cow
catch(Exception e) betN-n-
{ ) \Mwv&k1
e.printStackTrace (); K[Bq,nPo
} pZp|F
} qW[p .jN
4$J:A~2H]
//日志 =A&x d"
public static void log(String sMsg) '{WYho!
{ 5"xZ'M~=
System.err.println(sMsg); j>X;a39|
} 4a]m=]Hm
4&;.>{:;
w V&{w7
public static void log(int sMsg) =SPuOy8
{ b{qeu$GR
System.err.println(sMsg); g=.~_&O
} 'gd3 w~
} qG3 [5lti
jXq~ x"(
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/* -]"=b\Q
**TestMethod.java aZ^P*|_K3
*/ K}ACZT)Wp
package NetFox; Dv?'(.z
'bp*hqG[
xxOo8+kA
public class TestMethod { `"QUA G
g{wIdV
(v(!l=3
public TestMethod() gv$6\1
{ ///xx/weblogic60b2_win.exe z!27#gbL
try{ Gs%IZo_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1><\3+8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Q>f^*FyOw<
SiteFileFetch fileFetch = new SiteFileFetch(bean); Q/r0p>
fileFetch.start(); }ny,Nl
} L'=2Uk#.D
catch(Exception e){e.printStackTrace ();} ?P4@U9i
-IhFPjQ
$~c?qU
} 3?I^D /K^
0/P!rH9
iOz<n z
public static void main(String[] args) yo*c& >
{ MN\/F4Io
new TestMethod(); g/,fjM_
} 33x3zEUt6
} HpXMPHd
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