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)); :WejY`}H%
} b8v?@s~
for(int i=0;i<nEndPos.length-1;i++) jI0gQ [
{ B@dA?w.x
nEndPos = nStartPos[i+1]; p;Kw$fQ?
} 1{R1:`
nEndPos[nEndPos.length-1] = nFileLength; X.V7od>
} G&MI@Hq
} E`.dU<8HE
Hw[u Sv8
L!:}
//启动子线程 8)3g!3S
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; g83]/s+
for(int i=0;i<nStartPos.length;i++) x7 jE Ns )
{ qazM@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :a(er'A
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^yiRrcOo
nStartPos,nEndPos,i); [_ESR/&N
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); u$d T^c
fileSplitterFetch.start(); "1_eZ`
} XJTY91~R
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S{aK\>>H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); MDa 4U@Q
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", dN J2pfvv
nEndPos = " + nFileLength); h{I)^8,M
// fileSplitterFetch[nPos.length-1].start(); BKe~y
&^^zm9{
*?%DdVrO@
//等待子线程结束 #WlIH7J8Tc
//int count = 0; k2muHKBlk
//是否结束while循环 )xIk#>)
boolean breakWhile = false; jD9^DzFx
gy/z;fB
yU3fM?a
while(!bStop) hrPm$`
{ Lh0Pvq0C
write_nPos(); vFXih'=_
Utility.sleep(500); @D&VOJV
breakWhile = true; .p&4]6
uG@Nubdwuy
m[,! orq
for(int i=0;i<nStartPos.length;i++) ,Hn{nVU1R=
{ OF'y]W&
if(!fileSplitterFetch.bDownOver) B/g.bh~)q
{ wYK-YY:Q3
breakWhile = false; !8M]n
break; vx /NG$
} jHq.W95+P
} hb'S!N5m
if(breakWhile) ~itrM3^"w
break; .zO/8y(@
\wqi_[A
EE5I~k5
//count++; {Sm^F
//if(count>4) Vr0-evwfo
// siteStop(); f}b= FV{
} 21x?TZa
-Zd0[& ']
E'zLgU)r`
System.err.println("文件下载结束！"); {(#Dou
} H'Q4IRT
catch(Exception e){e.printStackTrace ();} 5%j !SVW
} `)$'1,]u
h-<2N)>!
:786Z,')
//获得文件长度 -t2bHhG
public long getFileSize() ?]SSmZpk
{ HM ;9%rtO
int nFileLength = -1; Svj%O(
try{ @DG$
URL url = new URL(siteInfoBean.getSSiteURL()); 6Pc3;X~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \zCT""'i
httpConnection.setRequestProperty("User-Agent","NetFox"); =n|n%N4Y
$lmGMljF
`b 6j7
int responseCode=httpConnection.getResponseCode(); jC7`_;>=
if(responseCode>=400) 9q;n@q:29
{ "pGSz%i-
processErrorCode(responseCode); }S|~^
return -2; //-2 represent access is error 3(l^{YC+[7
} daS l.:1
6jT+kq)
aj;OG^(!2_
String sHeader; F@ lJk|*_
R@Ch3l@
X}C}
for(int i=1;;i++) ^Rriu $\
{ H7!j5^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); A]^RV{P
//Utility.log(in.readLine()); L5 ~wX
sHeader=httpConnection.getHeaderFieldKey(i); Kt5;GUV
if(sHeader!=null) QyN<o{\FD!
{ :^7/+|}9p
if(sHeader.equals("Content-Length")) ]pC/6'
{ W=j
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); H.#<&5f
break; R@_i$Df|
} c+P.o.k;
} uaN0X"
else (F9U`1~4
break; -)_"7}|u5
} seO7/h_a
} KLi&TmIB
catch(IOException e){e.printStackTrace ();} YJi C}.4Q
catch(Exception e){e.printStackTrace ();} ]/>(C76
H0tjBnu
~kM# lh7At
Utility.log(nFileLength); J_) .Hd
SJ4[n.tPI
Q@zD'G>
return nFileLength; ha_&U@w
} #_)<~
QEo i9@3
?QuD:vck
//保存下载信息（文件指针位置） . AJ(nJ)
private void write_nPos() uEqL Dg
{ NVqJN$z
try{ ;Gf,$dbWn
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3Q'Q %2
output.writeInt(nStartPos.length); Te&F2`vo
for(int i=0;i<nStartPos.length;i++) \D Oqx
{ @T>\pP]o
// output.writeLong(nPos); F2jZ3[P
output.writeLong(fileSplitterFetch.nStartPos); LDilrG)
output.writeLong(fileSplitterFetch.nEndPos); "tax
} M'gw-^(
output.close(); );X&J:-l+
} );-?~
catch(IOException e){e.printStackTrace ();} AG?cI@',
catch(Exception e){e.printStackTrace ();} S+aXlb
} ;jC}.] _)w
4O}ZnE1[
t.0F
//读取保存的下载信息（文件指针位置） ^lADq']
private void read_nPos() xz5V.
{ :Y/>] tS4
try{ VHwAO:+-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _`'VOY`o
int nCount = input.readInt(); Wx~N1+
nStartPos = new long[nCount]; /{h@A~<96
nEndPos = new long[nCount]; /1A3 Sw
for(int i=0;i<nStartPos.length;i++) NrQGoAOw
{ -2Bkun4Pt
nStartPos = input.readLong(); #6w\r&R6
nEndPos = input.readLong(); %NH#8#';2
} O"%b@$p\L
input.close(); 3QNu7oo
} |"t)#BUtL
catch(IOException e){e.printStackTrace ();} 1>5l(zK!9
catch(Exception e){e.printStackTrace ();} 1< 22,
} U tb"6_
L;jzDng<
:x85:pa
private void processErrorCode(int nErrorCode) `[.b>ztqgJ
{ %ae|4u#b
System.err.println("Error Code : " + nErrorCode); ddR*&.Y!a
} \q2:1X|
@D$^- S6
9@'^}c#
//停止文件下载 D}.Pk>5
public void siteStop() +hoZW R
{ nd~cpHQR^
bStop = true; zn!H&!8&
for(int i=0;i<nStartPos.length;i++) w +pK=R
fileSplitterFetch.splitterStop(); &d5n_:^
K=S-p3\g
J3 Y-d7=|
} H]i.\2z
} 2L\}
//负责部分文件的抓取 Nu}x`Qkmr
**FileSplitterFetch.java G3[X.%g`
*/ v@_^h}h/,=
package NetFox; |AgdD
j%_{tB
?%)G%2
import java.io.*; ;^fGQ]`4
import java.net.*; j.}@9
|_fmbG
O$ p
public class FileSplitterFetch extends Thread { 'aj97b;lpG
mI$<+S1!
"#<P--E9
String sURL; //File URL g4p-$WyT8>
long nStartPos; //File Snippet Start Position }02#[vg
long nEndPos; //File Snippet End Position nw.,`M,N
int nThreadID; //Thread's ID I%4)%
boolean bDownOver = false; //Downing is over g3fxf(iY(
boolean bStop = false; //Stop identical no~Yet+<"
FileAccessI fileAccessI = null; //File Access interface 6A$ Y]u
jFE1k(2e
{DP%=4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException c;RL<83:
{ YTb/ LeuT
this.sURL = sURL; O{P@fv%~(o
this.nStartPos = nStart; 3c%dErch
this.nEndPos = nEnd; `lI(SS]w
nThreadID = id; 1]DPy+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 gfr y5e
} gAFu
[.ya&E)x
\my5E\
public void run() _lK+/"-l
{ aRt`IcZYz
while(nStartPos < nEndPos && !bStop) !Eqp,"ts7
{ VXfp=JE
F'NX
uD'GI
try{ u*W6fg/"
URL url = new URL(sURL); v|]1x2191
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7dg2-4
httpConnection.setRequestProperty("User-Agent","NetFox"); [unK5l4_!
String sProperty = "bytes="+nStartPos+"-"; QGC%, F"+
httpConnection.setRequestProperty("RANGE",sProperty); Un~ }M/
Utility.log(sProperty); {Yt@H
\w6A-daD0
Z30r|Ufh
InputStream input = httpConnection.getInputStream(); G8sxg&bf{
//logResponseHead(httpConnection); Xyz w.%4c
1o Z!Up0
#0:N$'SZ
byte[] b = new byte[1024]; gG?sLgL:
int nRead; _"4u?C#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) d_ [l{
{ f+WN=-F\
nStartPos += fileAccessI.write(b,0,nRead); jPDk~|
//if(nThreadID == 1) L\GjG&Y5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R&vV!d
} YA?46[:
$;k2b4u
2#y-3y<G
Utility.log("Thread " + nThreadID + " is over!"); 6=aXz2.f
bDownOver = true; [B2g{8{!
//nPos = fileAccessI.write (b,0,nRead); CO<P$al
} MS>QU@z7c
catch(Exception e){e.printStackTrace ();} n7>L&?N#y#
} "t ^yM`$5[
} {S$]I)tV
mdNIC
sMZ90Q$
//打印回应的头信息 m-wK8]t9
public void logResponseHead(HttpURLConnection con) 9 SBVp6'
{ _Hp[}sv4)
for(int i=1;;i++) G\PFh&
{ ]YF_c,Q
String header=con.getHeaderFieldKey(i); y\C_HCU H
if(header!=null) $sfDtnRy
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *vqr+jr9
Utility.log(header+" : "+con.getHeaderField(header)); 0t^Tm0RzH
else eBN!!Y:7
break; P {0iEA|k
} wf,B/[,d
} TF[8r[93
LBw$K0
Q7{/ T0
public void splitterStop() xG7/[ jG
{ _U<r@
bStop = true; 141G~@-
} 1SwKd*aRR?
GKg&lM!O$
S=^kR [O"
} ^C|N
/=i+7^
G.B~n>}JU,
/* "C~Zl&3
**FileAccess.java -ld1o+'`v!
*//文件访问(定位，写) QIWfGVc-
package NetFox; 6");NHE
import java.io.*; d95 $w8>
XD8Q2un
cq0#~20
public class FileAccessI implements Serializable{ vxt<}h5J/!
+#LD@)G
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Q|] 9
RandomAccessFile oSavedFile; mh:eUFe
long nPos; ^!j,d_)b!
ui!MQk+D9
n]<>$
public FileAccessI() throws IOException Xf/qUao
{ _Z0O]>KH
this("",0); #[ TOe
} ]7/6u.G7R
8w\ZY>d
*f*o ,~8V1
public FileAccessI(String sName,long nPos) throws IOException \-nbV#{
{ 1R"?X'w
oSavedFile = new RandomAccessFile(sName,"rw"); H]<@\g*l@P
this.nPos = nPos; T:|PSJc0
oSavedFile.seek(nPos); RK\$>KFE
} nN*:"F/^
av:9kPKm
`;v5o4.`
public synchronized int write(byte[] b,int nStart,int nLen) T@?uA*J
{ C#tY};t
int n = -1; 277Am*2
try{ H"vy[/UcR
oSavedFile.write(b,nStart,nLen); 6_zyPh
n = nLen; YkJnZ_k/P
} %1UdG6&J_
catch(IOException e) tGVC"a
{ M\L^ Wf9
e.printStackTrace (); c-".VF
} V")u y&Ob
'p> *4}
gu|cQ2xV
return n; Qs #7<NQ
} wxW\L!@
(-bLP
? f>pKe
} I?~iEO\nh
/xh/M@G3
1 [D,Mu%E
/* -8pQI
**SiteInfoBean.java dOx0'q"Z
*/ /^9KZj
package NetFox; fb;y*-?#
K)_DaTmi)
j3_vh<U\
public class SiteInfoBean { /{sFrEMP\
WcZck{ehd
o>?#$~XNv
private String sSiteURL; //Site's URL k=``Avp?
private String sFilePath; //Saved File's Path N799@:.
private String sFileName; //Saved File's Name >[&Zs3>
private int nSplitter; //Count of Splited Downloading File 0$1-5XY9
WJs2d73Qp
72akOx
public SiteInfoBean() ])D39
{//nSplitter的缺省值为5 79G& 0 P\
//default value of nSplitter is 5 6ntduXeNVh
this("","","",5); M.h8Kr!.
} Pp~:e}
p)y'a+|7
-V'h>K
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (I0QwB
{ am(jmf::
sSiteURL= sURL; ]<g`rR7}
sFilePath = sPath; t/Y)%N
sFileName = sName; xa]e9u%
this.nSplitter = nSpiltter; ['#3GJz-
)a0%62
;($"_h
} /^^wHW:
R8n/QCeY{
JR^#NefJ
public String getSSiteURL() N2/t
{ `zjbyY
return sSiteURL; -JwwD6D
} LqcHsUFj
riz[AAB
d%w#a3(
public void setSSiteURL(String value) Lcow2 SbH
{ A{,ZfX;SPO
sSiteURL = value; ~3r}6,%
} #24eogo~
~uRL+<.c
9f7T.}HM
public String getSFilePath() \$[; d:9j
{ ]aqg{XdGt
return sFilePath; = k7}[!T
} TL*8h7.(
oJ`cefcWo
]^c]*O[8
public void setSFilePath(String value) 'pQ\BH
{ wD|I^y;
sFilePath = value; =lG/A[66
} ml\2%07
p"k[ac{
tShyG!b
public String getSFileName() VY]L<4BfGL
{ '%\FT-{
return sFileName; 4 /Q4sE~<
} ed:[^#Lj
nQ}$jOU&
rUOl+p_47
public void setSFileName(String value) *CS2ndp
{ Y}UVC|Ef
sFileName = value; M,(UCyT
} V<W$h`
nr>Os@\BU
@?YO_</
public int getNSplitter() u>-pgu
{ f\]splL
return nSplitter; `%nj$-W:
} hH])0C
/@`kM'1:
sBV})8]KM
public void setNSplitter(int nCount) Z@d(0 z
{ @24)*d^1
nSplitter = nCount; 9zs!rlzQ
} u/S{^2`b
} &>$+O>c ,
3qNLosm#M
(//f"c]/
/* Gr}lr gPS
**Utility.java ~4'AnoD1w
*/ 0oiz V;B5%
package NetFox; 1p }:K`#{
0kOl,%Ey
=>en<#[\:
public class Utility { Yp(F}<f?
#cdrobJ
~;uc@GGo
public Utility() m2h@*
{ *%;+3SV
RwyRPc_
l:$i}.C
} MeMSF8zSQ
NPY\ >pf
//线程睡眠 f&ri=VJY\T
public static void sleep(int nSecond) &w"1VOV<
{ lwj,8
try{ 0<'Q;'2* L
Thread.sleep(nSecond); /ij)[WK@
} ;.EW7`)Z
catch(Exception e) 6X`i*T$.
{ ).D+/D/"2
e.printStackTrace (); \#O}K
} guc[du
} \Jy/ a-
}?KfL$@$
//日志 ]sL)[o
public static void log(String sMsg) K#_x.:<J
{ 5@&{%99
System.err.println(sMsg); JT(6Uf
} }X?M6;$)
wcW8"J'AH
(eEs0
public static void log(int sMsg) T\3aT
{ ]R?{9H|jwE
System.err.println(sMsg); 6! .nj3$*
} HJ^SqSm
} yNU.<d 5
|18h p
9qcA+gz:|
/* gR\-%<42
**TestMethod.java nEgDwJ<wl
*/ %TUvH>;0
package NetFox; M|DVFC
;FfDi*S7
3 jRI@
public class TestMethod { K0xka[x=(
YggeKN
&'KJh+jJ
public TestMethod() 4M,Q{G|e
{ ///xx/weblogic60b2_win.exe Z(c3GmY
try{ -{O>'9'1A
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); MFzJ 8^.1R
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b;k3B7<
SiteFileFetch fileFetch = new SiteFileFetch(bean); OPe3p {]
fileFetch.start(); )oAxt70
} lNRGlTD%
catch(Exception e){e.printStackTrace ();} SR8)4:aKW
Q!*}^W
-'%>Fon
} F)n^pT
g:rjt1w`D
F :p9y_W
public static void main(String[] args) =&~7Q"
{ 9S_PZH
new TestMethod(); vOQ 3A%/
} 1=U NA :t<
} 68 \73L=
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