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)); =20Q!wcu
} Tmw :w~
for(int i=0;i<nEndPos.length-1;i++) GXHk{G@TS
{ u\t ;
nEndPos = nStartPos[i+1]; MGmtA(
} .3HC*E.e
nEndPos[nEndPos.length-1] = nFileLength; 4AF"+L
} W}.4$f>
} EO| kiC
h+$_:](PC
H!45w;,I
//启动子线程 h_CeGl!M}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; _k j51=
for(int i=0;i<nStartPos.length;i++) 0p[$8SCJ
{ 3'.OghI
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 01w=;Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (U7%Z<
nStartPos,nEndPos,i); H=yD}!j
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WO}JIExy
fileSplitterFetch.start(); 8D+OF 6CM
} gE$dz#t.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T`WFY
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0kiW629o
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", f}+G;a9Nj
nEndPos = " + nFileLength); [C d2L&9
// fileSplitterFetch[nPos.length-1].start(); ^|sQkufo
2nEj X\BY
?>AhC{
//等待子线程结束 !'[sV^ds
//int count = 0; v4ueFEY
//是否结束while循环 FS@SC`~(
boolean breakWhile = false; vb70~k
\<PX'mnO
<`N\FM^vo
while(!bStop) M(2[X/t
{ zJx<]=]
write_nPos(); chiQ+
Utility.sleep(500); T+~~w'v0
breakWhile = true; 6%yr>BFtVV
L4[bm[x
z5i!GJB
for(int i=0;i<nStartPos.length;i++) r^\^*FD |
{ rgP$\xn-
if(!fileSplitterFetch.bDownOver) |Y])|`_'G
{ (JM4W "7'
breakWhile = false; M!I:$DZt
break; wLgRI$_Dm
} h]D=v B
} q,*IR*B:a
if(breakWhile) T}\U:@b
break; iYnw?4Y
I&cb5j]C
nrf%/L
//count++; MT V'!Zxs
//if(count>4) pw$I~3OFd
// siteStop(); $OUa3!U_!
} &bL1G(}
nTHP~]
fqr}tvMr=T
System.err.println("文件下载结束！"); 9:kb0oBa?l
} N..u<06j/
catch(Exception e){e.printStackTrace ();} da-3hM!u+
} Q \{\uJ x
prm
<<A@69"4n
//获得文件长度 leD?yyjw7
public long getFileSize() 9j,zaGD0
{ *3k~%RM%?
int nFileLength = -1; @TH \hr]
try{ |Jq/kmn
URL url = new URL(siteInfoBean.getSSiteURL()); J*;t{M5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); pH*L8tT
httpConnection.setRequestProperty("User-Agent","NetFox"); fe Q%L
d)0%|yX6
6=kd4'yV
int responseCode=httpConnection.getResponseCode(); kB8l`| I
if(responseCode>=400) |_ @iaLE
{ tl4;2m3w
processErrorCode(responseCode); ML'R[~|
return -2; //-2 represent access is error x x 'XR'zK
} O-G@To3\
F0|T%!FB>%
AI)9E=D%
String sHeader; 'Gc6ZSLM
"90}H0(+
<D 5QlAN
for(int i=1;;i++) $DQ -.WI
{ Y#Z&$&n
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); bWyXDsr+
//Utility.log(in.readLine()); ,wFLOfV@
sHeader=httpConnection.getHeaderFieldKey(i); 7<KRB\)b&
if(sHeader!=null) FIS-xpv$
{ `"bm Hs7
if(sHeader.equals("Content-Length")) rLVAI#ci=
{ Im Tq`
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); MKH7d/x
break; p\,lbrv
} TJVNR_x
} Zc"]Cv(
else [OT@gp:
break; 6^wiEnA
} ~{N|("nB
} z1L.
catch(IOException e){e.printStackTrace ();} x:@e ID
catch(Exception e){e.printStackTrace ();} Oa7W&wi
6znm?s@~
sX=!o})0
Utility.log(nFileLength); |M0TG
~svu0[Vx
2f-Z\3)9 J
return nFileLength; $4L=Dg
} E+Gea[c
))MP]j9 T
U} g%`<
//保存下载信息（文件指针位置） B(>_.x#kv
private void write_nPos() ~L1N1Z)Kk
{ n_w,Ew,>5
try{ 36j.is
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1%+0OmV&
output.writeInt(nStartPos.length); ;J`X0Vl$
for(int i=0;i<nStartPos.length;i++) ]f-e/8$`@
{ ,%:`Ll t]$
// output.writeLong(nPos); p3Gj=G
output.writeLong(fileSplitterFetch.nStartPos); F4PD3E_#
output.writeLong(fileSplitterFetch.nEndPos); @hv9=v+
} 5G2u(hx
output.close(); Tq?W @DM*
} X)|%[aX}q
catch(IOException e){e.printStackTrace ();} `SU;TN0
catch(Exception e){e.printStackTrace ();} xr=f9?%R
} pu^1s#g8w
f8n'9HOw>
]-q:Z4rb
//读取保存的下载信息（文件指针位置） tF;aB*
private void read_nPos() kP|!!N
{ ^@ux
try{ ZuE0'9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); PJ_|=bn
int nCount = input.readInt(); 1DBzD%@Oz
nStartPos = new long[nCount]; 6suc0
nEndPos = new long[nCount]; G(4k#jB
for(int i=0;i<nStartPos.length;i++) 00Rk%QV
{ y_nh~&
nStartPos = input.readLong(); .5T7O_%FP
nEndPos = input.readLong(); {!="PnB
} 6z(_^CY
input.close(); 1"k +K~:
} j9,X.?Xvx
catch(IOException e){e.printStackTrace ();} {wm `
catch(Exception e){e.printStackTrace ();} *R:nB)(6<
} 'R$~U?i8
J)(pGS@
EuAa
private void processErrorCode(int nErrorCode) :')<|(Zy
{ 65}:2l2<
System.err.println("Error Code : " + nErrorCode); o 1b#q/
} 0 Hq$h
A76=^iw
c=K M[s.
//停止文件下载 7j]@3D9[:p
public void siteStop() 6D+9f{~r
{ d EXw=u
bStop = true; (2{1m#o
for(int i=0;i<nStartPos.length;i++) J|>P,x#G
fileSplitterFetch.splitterStop(); \ pq]q
FYi<+]HZ
#a0 (Wh7
} g"!B |
} i^W\YLE
//负责部分文件的抓取 H<>x_}&
**FileSplitterFetch.java 5n"'M&Ce
*/ )PwDP
package NetFox; ;^xku%u
Z2ZS5a
c2y5[L7?
import java.io.*; KSexG:Xb
import java.net.*; AvwX 2?tc
._nhW*
%++q+pa
public class FileSplitterFetch extends Thread { p'R}z|d)
?iq:Gf
i\3`?d
String sURL; //File URL l^SKd
long nStartPos; //File Snippet Start Position AKHi$Bk
long nEndPos; //File Snippet End Position M^bujGD
int nThreadID; //Thread's ID <?I~ +
boolean bDownOver = false; //Downing is over v3[ 2!UXq
boolean bStop = false; //Stop identical U"ZDt
FileAccessI fileAccessI = null; //File Access interface =A,i9Z&
[3\}Ca1
ge E7<"m%
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +`9T?:fu
{ VJPt/Dy{
this.sURL = sURL; 8L&#<Ol
this.nStartPos = nStart; 8J@REP4
this.nEndPos = nEnd; OW6i2>Or
nThreadID = id; Z*oGVr g
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Gz kf
} f-3lJ?6
1|Fukx<@J<
p{88v3b6
public void run() BK-{z).)
{ >`t |a
while(nStartPos < nEndPos && !bStop) M,7v}[Tbl
{ T]0qd^\4w
9]|cs
uv Z!3UH.
try{ g4U%(3,>D
URL url = new URL(sURL); k/*r2 C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %SIbpk%
httpConnection.setRequestProperty("User-Agent","NetFox"); 0Pbv7)=XL
String sProperty = "bytes="+nStartPos+"-"; SkS vu}
httpConnection.setRequestProperty("RANGE",sProperty); Qxt,@<IK
Utility.log(sProperty); Es)Kw3^a
B1\}'g8%f
$2\OBc=
InputStream input = httpConnection.getInputStream(); \QQw1c+
//logResponseHead(httpConnection); 2y,f
`2}Mz9mk
RtN5\
byte[] b = new byte[1024]; Z+E@B>D7A^
int nRead; >12phLu
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) va| 1N/&
{ 6>zO"9
nStartPos += fileAccessI.write(b,0,nRead); xa??OT`(
//if(nThreadID == 1) yX/ 9jk
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {QI"WFdGx
} >q"mI6F
TU^UR}=lP
[Jwo,?w
Utility.log("Thread " + nThreadID + " is over!"); 3N[t2Y1r
bDownOver = true; Qv|A^%Ub!
//nPos = fileAccessI.write (b,0,nRead); 8-+Ce;h
} j0>Q:hn
catch(Exception e){e.printStackTrace ();} B&VruOP0
} 1 VcZg%I
} 4Un(}P'
( hp 52Vse
^cn%]X#.
//打印回应的头信息 -X3yCK?re
public void logResponseHead(HttpURLConnection con) JUHmIFjZ
{ i]Njn k
for(int i=1;;i++) VG_ PBG(
{ iz.J._&
String header=con.getHeaderFieldKey(i); (_ HwU/
if(header!=null) {CdQ)|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Cjc>0)f&.
Utility.log(header+" : "+con.getHeaderField(header)); $SQUN*/>
else #rD0`[pz
break; yS'W ss
} @y]ek/
} P{-j^'y
f#f<Ii
<Nwqt[.
public void splitterStop() H65><38X/
{ z@Pv~"
bStop = true; +Nn $
} MVP|l_2!
lY -2e>
uGt}Hn
} fqpbsM;M]
<;kcy :s
",O |uL
/* wIQ~a
**FileAccess.java CiF(
*//文件访问(定位，写) 6Ft?9 B(F:
package NetFox; .Q!_.LX
import java.io.*; GBeWF-`B
3EkCM_]
L)(JaZyV5
public class FileAccessI implements Serializable{ .bYZkO:oy
LY:%k|L9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5-*hAOThg
RandomAccessFile oSavedFile; )+7|_7 !x
long nPos; Eqizx~eqq
|#(KP
"%peYNZ&%
public FileAccessI() throws IOException $|"Y|3&X
{ (/gv U80
this("",0); .q90+9Ek=
} d6^:lbj
*jR4OY|DXH
#B2a?
public FileAccessI(String sName,long nPos) throws IOException ~ECIL7,
{ t|PQ4g<
oSavedFile = new RandomAccessFile(sName,"rw"); _"%hcCMw
this.nPos = nPos; ^/~ZP?%]
oSavedFile.seek(nPos); 2t7P| b~V1
} dl]pdg<
9\'JtZO
r1axC%
public synchronized int write(byte[] b,int nStart,int nLen) *"nN To
{ "hmLe(jo}
int n = -1; HKL/D
try{ 5^ck$af
oSavedFile.write(b,nStart,nLen); `5Bv2wlIV
n = nLen; WKAG)4
} G{.[o6>
catch(IOException e) 5rb<u>e{
{ ,<=gPs;x
e.printStackTrace (); jn4|gQ
} J`]9n>G
AQ&vq$
pwH*&YU
return n; 0u;a*#V@
} S{m:Iij[;
Kf-XL),3l
2qdc$I&$
} &S=Qu?H
cQkj{u
Y\Z6u)
/* ppo.#p0w
**SiteInfoBean.java s3Wjhw/
*/ 9Af nMD
package NetFox; fH@cC`
4.Q[Tu
?)ct@,Ek$
public class SiteInfoBean { Jkv!]C
25f[s.pv8
$Zr \$z2
private String sSiteURL; //Site's URL x<`^4|<
private String sFilePath; //Saved File's Path Ee_?aG e&
private String sFileName; //Saved File's Name Wks zNh
private int nSplitter; //Count of Splited Downloading File ce;$)Ff\
lN&+<>a
8[.&ca/[
public SiteInfoBean() 2ql)]Skg6
{//nSplitter的缺省值为5 k.7!)jL7
//default value of nSplitter is 5 q44vI
this("","","",5); A;5_/ 2
} T+x /J]A
}.(DQwC}1k
MQDLC7Y.p5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) bo/<3gR
{ ePZAi"k
sSiteURL= sURL; Y4w]jIv
sFilePath = sPath; giH#t< )W
sFileName = sName; =E$bZe8
this.nSplitter = nSpiltter; [NJ2rQ/w7
]8R@2L3s
1ni72iz\
} n&o"RE 0~0
KgbBa2@+
vz#-uw,O:
public String getSSiteURL() pacD7'1{
{ ,}khu
return sSiteURL; p^}`^>OL
} %sPze]
gG@4MXq.
yY!)2{F+
public void setSSiteURL(String value) {qlcTc
{ q.<)0nk
sSiteURL = value; l.]wBH#RS
} w N`Njm9!
r~JGs?GH
vE8BB$D
public String getSFilePath() oH&@F@r:+
{ @;KYvDY
return sFilePath; YjnQ@IfIH
} IiRQ-,t1
(J.Z+s$:2
TBrwir
public void setSFilePath(String value) X`EVjK
{ wkPjMmW+!
sFilePath = value; ^|zag
} IY8<^Q']
rM,f7hm[S*
t2vm&jk
public String getSFileName() ZA. SX|m
{ k!z<=WA
return sFileName; -BI!ZsC'
} @k)J i!7
YmFg#eS
g 8uq6U
public void setSFileName(String value) F .Zk};lb
{ kr~n5WiAZ
sFileName = value; wu eDedz\
} Lfcy#3!
%*!6R:gAp
0{%@"Fb0O
public int getNSplitter() ME0u|_dPjz
{ nyqX\m-
return nSplitter; vV$t`PEY
} uq-`1m}
vdvnwzp!l
l1lYb;C
public void setNSplitter(int nCount) 4H,c;g=!
{ P (7Q8i'
nSplitter = nCount; %i/|}K
} w' J`$=
} Q|{b8K
[jlum>K
"P@ SR`v#
/* ~+0IFJ`}
**Utility.java `:~Wu/Ogr
*/ ,{S $&g*
package NetFox; %Rf9KQ
#oa>Z.?_V
/;Hqv`X7
public class Utility { BF2U$-k4
Ri`6X_xU
!*~QB4\2b
public Utility() i.W*Go+
{ bri8o"
&}Wi@;G]2
7- LjBlH
} C{^I}p
LXxQI(RO
//线程睡眠 _+aR|AEC
public static void sleep(int nSecond) /D;ugc*3
{ U7jDm>I
try{ k*6"!J%A
Thread.sleep(nSecond); b:~#;$g
} {*hvzS{1d
catch(Exception e) n!~ $Z/
{ u&S0
e.printStackTrace (); fgj$ u
} U _A'/p^D
} >0ZG&W9
GXD<X_[
//日志 9)S3{i6w
public static void log(String sMsg) <+q`Dk
{ :NWIUN
System.err.println(sMsg); Z&iW1
} <a=OiY
]R}(CaT1
yFmy
public static void log(int sMsg) M6Xzyt|
{ hO3 q|SL
System.err.println(sMsg); >m;nt}f'+
} sm{0o$\Z
} nu1XT 1q1
*BM#fe
2!W[ff@~7
/* /8l@ndZf
**TestMethod.java : KFK2yD
*/ pi#a!Quf\
package NetFox; `'XN2-M8
F|m &n&
73'AQ")UJ
public class TestMethod { M1NdlAAf
!Z\Gv1
z>,tP
public TestMethod() _fY9u2Y
{ ///xx/weblogic60b2_win.exe i g7|kl
try{ 0$-|Th:o
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); D8~\*0->
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); k%Tp9x$
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?#&[1.= u
fileFetch.start(); >m!Z$m([J
} TTa3DbFp%
catch(Exception e){e.printStackTrace ();} ,38M6yD
acUyz2x
hPG@iX|V
} w<h8`K`3
L.-qTh^P
|k]]dP|:'
public static void main(String[] args) jxm#4
{ <<gW`KF
new TestMethod(); z ULHgG
} ?-3G5yy
} *Od?>z
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