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)); =F^->e0N
} }iiG$?|.
for(int i=0;i<nEndPos.length-1;i++) fl5UY$a2-
{ YW4bm
nEndPos = nStartPos[i+1]; _{2Fx[m%
} 3isXgp8
nEndPos[nEndPos.length-1] = nFileLength; wB1-|=K1
} Pq[0vZ_}dN
} NIWI6qCw
]ut-wqb{p
o3\SO
//启动子线程 u~naVX\3b
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 84hi, S5P
for(int i=0;i<nStartPos.length;i++) .yFg$|yG
{ M2zos(8g
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "c!oOaA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "df13U"
nStartPos,nEndPos,i); (>+k3
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5tgILxSK
fileSplitterFetch.start(); Hb@G*L$
} 4$q)e<-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _x,-d|9bd
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }]n>A
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", lD;,I^Lt6
nEndPos = " + nFileLength); x|,aV=$o
// fileSplitterFetch[nPos.length-1].start(); `ykMh>*{
ziB]S@U
N18diP[C
//等待子线程结束 dEAAm=K,<
//int count = 0; 2EqsfU* I
//是否结束while循环 =yhn8t7@]
boolean breakWhile = false; <g/(wSl
H8o%H=I%
8 /RfNGY
while(!bStop) >2/wzsW
{ QBPvGnb
write_nPos(); #<WyId(
Utility.sleep(500); U~){$kpI#
breakWhile = true; !e#I4,fn
Vgru, '
_/z)&0DO
for(int i=0;i<nStartPos.length;i++) _]?Dt%MkD
{ G\,A> mT/P
if(!fileSplitterFetch.bDownOver) uz#eO|z@o
{ ;*37ta
breakWhile = false; q_T?G e
break; u_[4n
} tmY-m,U
} .1[2 CjQ
if(breakWhile) QE{;M
break; dPyBY]`
1$3XKw'
faL^=CAe
//count++; S\{^LVXTMd
//if(count>4) ~d#;r5>
// siteStop(); Y+"hu2aPkY
} )o'U0rAx|a
&"H<+>`
:zn ?<(sQ
System.err.println("文件下载结束！"); %9-#`
} @cTZ`bg
catch(Exception e){e.printStackTrace ();} .^N#|hp^
} 8)q]^
mb*h73{{
+N(YR3
//获得文件长度 i6g[E4nk
public long getFileSize() 1A/c/iC
{ ncw?;
int nFileLength = -1; c^[1]'y
try{ (zTI)EV
URL url = new URL(siteInfoBean.getSSiteURL()); = "hY{RUa
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2cX"#."5p
httpConnection.setRequestProperty("User-Agent","NetFox"); yY@s(:
,0<F3h
X?}GPA4 W
int responseCode=httpConnection.getResponseCode(); $vbAcWj
if(responseCode>=400) B,m$ur#$
{ }2!5#/^~
processErrorCode(responseCode); 3EW f|6RI
return -2; //-2 represent access is error UN .[,%<s
} TLL[F;uZ
6t mNfI34
_F/lY\vm
String sHeader; E_gDwWot
LN3dp?;_{
"JUQ)> !?
for(int i=1;;i++) ]x(2}h^S
{ !K^Z5A_;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); s*~jvL
//Utility.log(in.readLine()); :Z]+Z_9p
sHeader=httpConnection.getHeaderFieldKey(i); )zLS,/pk^
if(sHeader!=null) f w>Gx9
{ + x;ML
if(sHeader.equals("Content-Length")) 5N3!!FFE
{ HfeflGme*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]R0A{+]n
break; t1{%FJ0F
} feq6!k7
} kx:lk+Tx
else Q"K>ML>0
break; A7,$y!D
} 2p;}wYt
} n.qxxzEN
catch(IOException e){e.printStackTrace ();} Z"%O&O
catch(Exception e){e.printStackTrace ();} /%q9hI
Nj@?}`C 4
$8T|r+<
Utility.log(nFileLength); >LaL!PnZ
<iprPk
D15u1A
return nFileLength; qL;T&h
} `=l{kBZT|
\A\yuJ=
=wR]X*Pan
//保存下载信息（文件指针位置） 'hi\98y
private void write_nPos() :iNAXy
{ r5qx! >
try{ IOSoc 7+"
output = new DataOutputStream(new FileOutputStream(tmpFile)); $}nUK~$GSv
output.writeInt(nStartPos.length); 'St= izhd
for(int i=0;i<nStartPos.length;i++) =&b$W/l)0
{ -S3+ h$Y8
// output.writeLong(nPos); 5NvyK[w]
output.writeLong(fileSplitterFetch.nStartPos); ${?exnb$
output.writeLong(fileSplitterFetch.nEndPos); &'ETx"
} u+gXBU
output.close(); 6ewOZ,"j"4
} a&c#* 9t{
catch(IOException e){e.printStackTrace ();} 1 l*(8!_
catch(Exception e){e.printStackTrace ();} q{+poVX
} P$qkb|D,
V?J,ab$X#
1o8"==n%
//读取保存的下载信息（文件指针位置） >/`cmNmb
private void read_nPos() bq&S?! =s
{ GuY5 %wr
try{ <w2NJ~M^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6.7Kp
int nCount = input.readInt(); -Tkd@
nStartPos = new long[nCount]; Y&!]I84]
nEndPos = new long[nCount]; 898wZ{9
for(int i=0;i<nStartPos.length;i++) lgqL)^8A
{ j}.J$RtW1f
nStartPos = input.readLong(); `8.32@rUB.
nEndPos = input.readLong(); 4Hpu EV8Q
} utl=O
input.close(); GGL4<P7
} = hX-jP
catch(IOException e){e.printStackTrace ();} U+r#YE.
catch(Exception e){e.printStackTrace ();} v9`B.(Ru
} ~)8i5p;P/k
|Ge/|;.v`
3a)Q:#okD
private void processErrorCode(int nErrorCode) R}6la.mQ
{ Tocdh.H|
System.err.println("Error Code : " + nErrorCode); n_&)VF#n(
} %s :
A-Pwi.$
NEou2y+}
//停止文件下载 qVe6RpS
public void siteStop() vMdhNOU
{ Lz{T8yvZ
bStop = true; 2&K|~~
for(int i=0;i<nStartPos.length;i++) P:-/3
fileSplitterFetch.splitterStop(); 7Z~szD
lnSE+YJ>
'*;eFnmvs:
} |{IU<o x
} @wgGnb)
//负责部分文件的抓取 AG\852`1m
**FileSplitterFetch.java }ZVv
*/ BOQV X&g%
package NetFox; si.a]k/f
$5CY<,f
9x^ /kAB
import java.io.*; m:Cx~
import java.net.*; 4x?u5L 9o
9.#R?YP$
>8;%F<o2
public class FileSplitterFetch extends Thread { A'-YwbY
C{,] 1X6g
YIUmCx0a
String sURL; //File URL &Wz:-G7<n
long nStartPos; //File Snippet Start Position +pViHOJu&V
long nEndPos; //File Snippet End Position ',s7h"
int nThreadID; //Thread's ID P(nHXVSUE
boolean bDownOver = false; //Downing is over PjZvLK@a9)
boolean bStop = false; //Stop identical #I~dv{RX
FileAccessI fileAccessI = null; //File Access interface PH%gX`N
;~$ $WU
7:q-NzE\6
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Or)c*.|\
{ +Qb/:xQu
this.sURL = sURL; *xTquV$
this.nStartPos = nStart; ;p!hd}C
this.nEndPos = nEnd; :BxYaAVt^
nThreadID = id; &0Zk3D4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^K8a#-
} |8{iIvi/
w/W?/1P>q
~EkGG .
public void run() Q09~vFBg
{ 58'y~Ou
while(nStartPos < nEndPos && !bStop) 2#M:JgWV
{ }gRLW2&mR>
f8jz49C
n(Op<
try{ "hY^[@7 W
URL url = new URL(sURL); >,vW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?'m5)Z{
httpConnection.setRequestProperty("User-Agent","NetFox"); x)Kh_G
String sProperty = "bytes="+nStartPos+"-"; Tm.w+@
httpConnection.setRequestProperty("RANGE",sProperty); slO9H6<
Utility.log(sProperty); '^3pF2lIw
q ? TI,
Jd6Q9~z#
InputStream input = httpConnection.getInputStream(); B_jI!i{N%o
//logResponseHead(httpConnection); }C`0" 1
8&hn$~ate
Dohe(\C@
byte[] b = new byte[1024]; W%Q>< 'c
int nRead; >Nl~"J|]q
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >M85xjXP
{ 7gmMqz"z(>
nStartPos += fileAccessI.write(b,0,nRead); *`'%tp"'+
//if(nThreadID == 1) ,8?*U]}
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &?sjeC_
} usf(U>
-vAG5x/,
!O_^Rn+<2
Utility.log("Thread " + nThreadID + " is over!"); >8t[EsW/
bDownOver = true; &`2*6 )qa
//nPos = fileAccessI.write (b,0,nRead); [;8fL
} Xb 1^Oj
catch(Exception e){e.printStackTrace ();} ;K-t
} :S6 <v0`Z
} vJ}
vz5RS
m|FONQ,@D
//打印回应的头信息 LOkDx2@g
public void logResponseHead(HttpURLConnection con) LgKEg90w(
{ R!xc$`N
for(int i=1;;i++) 4>`w9
{ bGO_y]Pc
String header=con.getHeaderFieldKey(i); yN%Pe:R
if(header!=null) cNCBbOMr
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r T$g^
Utility.log(header+" : "+con.getHeaderField(header)); -z1o~~
else V t;&2v
break; >m{-&1Tx
} vA~hkkj{
} R$`T"C"
A1T;9`E
sJ()ItU5i
public void splitterStop() ~3]8f0^%m
{ [T|1Qq7
bStop = true; )dDmq
} (:]iHg3
WTN!2b
,W;8!n0
} -bQvJ`iF
H}rP{`m
NO1]JpR
/* 8Wp1L0$B
**FileAccess.java CMUphS-KE
*//文件访问(定位，写) `&JA7UD>
package NetFox; Py<vN!
import java.io.*; <-7Ha_#
x9s`H)
9j9?;3;
public class FileAccessI implements Serializable{ f89<o#bm7h
36UWoo
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5OE?;PJ(
RandomAccessFile oSavedFile; 6Z:|"AwC2
long nPos; M!@[lJ
3E:<
[-a/]
public FileAccessI() throws IOException l).Ijl}AH;
{ B`Pi\1H6%
this("",0); B)*%d7=x
} NYRNop( N#
UkQocZdZ
1-<Xi-=^{t
public FileAccessI(String sName,long nPos) throws IOException qILr+zH
{ <3OV
oSavedFile = new RandomAccessFile(sName,"rw"); |[ofc!/
this.nPos = nPos; $nWmoe)
oSavedFile.seek(nPos); =z.AQe+
} 2Ta F7Jn
)BDi2: u
=B2=UF
public synchronized int write(byte[] b,int nStart,int nLen) vS<e/e+
{ 2YQ$hL~
int n = -1; $E6uA}s
try{ b2H6}s"=w
oSavedFile.write(b,nStart,nLen); 9!h+LGs(,
n = nLen; ~.tu#Y?
} K*[wr@)u
catch(IOException e) ['j,S<Bu~
{ oQO3:2a
e.printStackTrace (); \GPc_m:qL
} "zc!QHpSd
c:5BQr '
<u\G&cd_tA
return n; #^Y-*vf2
} qB`P7!VN^]
2{\Y<%.
}_x oT9HUr
} 8%B @[YDe
__[q`
M"V@>E\L
/* >LSA?dy!?
**SiteInfoBean.java 52,a5TVG
*/ 75u*ZMK
package NetFox; %iNDRLR%I
|xOOdy6 )~
HIAd"}^
public class SiteInfoBean { &gfQZxT
~x+w@4)a>
HN! l-z
private String sSiteURL; //Site's URL ~ln,Cm} 4
private String sFilePath; //Saved File's Path ebchHnOd
private String sFileName; //Saved File's Name ,58[WZG
private int nSplitter; //Count of Splited Downloading File ^C{a'
~qF9*{~!
f#jAjzmYL
public SiteInfoBean() zb(u?U
{//nSplitter的缺省值为5 +TX]~k79Oq
//default value of nSplitter is 5 =&'j;j
this("","","",5); WUWQcJj
} KN=Orx7Gy
}e$);A|
V RL6F2 >6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) O<*iDd`(e
{ (;h\)B!o
sSiteURL= sURL; <LE>WfmC
sFilePath = sPath; =9M-N?cV
sFileName = sName; *V/SI E*8
this.nSplitter = nSpiltter; X}Lp!.i9o
RzkJS9)m
LO229`ARr|
} FoLwS%+yO
JkmL'Zk>:
6Jm4?ex
public String getSSiteURL() :?TV6M
{ h)rHf3:
return sSiteURL; /T@lHxX
} mAMKCxz,
qJ!xhf1
T&%>/7I>
public void setSSiteURL(String value) -T>`PJpJuL
{ Z.<B>MD8^
sSiteURL = value; MX34qJ9k
} mP-+];gg
Xo,BuK&G
-mXEbsm
public String getSFilePath() %`~8j H@
{ 1JM~Ls%Z
return sFilePath; Y9u2:y!LdL
} %<klz)!t
9Y(<W_{/
lk}x;4]Z
public void setSFilePath(String value) CH2o[&
{ Msf yIB
sFilePath = value; R~b$7jpd
} :V [vE h
X qh+
_LK(j;6K}
public String getSFileName() C5m*pGImG
{ G100L}d"N
return sFileName; ;Wr$hDt^
} 5ZPl`[He
)wC>Hq[mhW
Y9C]-zEv
public void setSFileName(String value) zr,jaR;
{ Cpr}*A
sFileName = value; p|Ln;aYc
} &EMm<(.]a
sU>*S$X8
</eh^<_~
public int getNSplitter() Z?~7#F~Z`
{ C][`Dk\D{
return nSplitter; vi'K|[!?
} r6A7}v
UuN(+&oD-
umi#Se3&
public void setNSplitter(int nCount) J[9jNCq|
{ 9QpKB c
nSplitter = nCount; Qtk'^Fc
} ]fR 3f
} V!oyC$eV
`jJb) z3D
:Qf^@TS}O
/* 6D$xG"c
**Utility.java |(wx6H:
*/ k&Sg`'LG8
package NetFox; 'h:4 Fzo<
% R'eV<
3vy5JTCz~
public class Utility { j"f]pzg&
)%Y$FLB
hM;EUWv
public Utility() 0j3j/={|.1
{ 7JujU.&{6
/q]WV^H
$jm'uDvm
} A/'G.H
Q (`IiV
//线程睡眠 Na#2sb[)
public static void sleep(int nSecond) HGPbx$!
{ f1JvP\I0Q
try{ /({5x[
Thread.sleep(nSecond); /GEqU^ B
} :r|dXW
catch(Exception e) bO-8<IjC_3
{ ?L_#AdK
e.printStackTrace (); *FO']D
} ~Su>^T(?-
} thS#fO4]d
*G=n${'
//日志 Y#uf 2>J
public static void log(String sMsg) xe 6x!
{ _I2AJn`#
System.err.println(sMsg); uu(.,11`
} "3Ec0U \s
;v.l<AOE
$?0<rvGJ
public static void log(int sMsg) 1y 6H2
{ ~,ac{%8x
System.err.println(sMsg); %e3lb<sv6
} +^`c"qJo
} D|OX]3~
Q}G
b+hZ<U/
/* :V`q;g
**TestMethod.java z.7 UfLV9
*/ _c`Gxt%
package NetFox; P4s:wuJ^
64[j:t=N
7pkc*@t
public class TestMethod { -OoXb( I4
$+$+;1[
sjztT<{Q^-
public TestMethod() t@b';Cuv
{ ///xx/weblogic60b2_win.exe #*?a"
try{ a}MOhM6T
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); GX(p7ZgB2
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); F+9|D
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9erTb?@S
fileFetch.start(); jMgNi@
} >:8GU f*
catch(Exception e){e.printStackTrace ();} ^8B#-9Ph b
?9/%K45
0^zu T
} VYvHpsI
*S*;rLH9c
%]d^B|
public static void main(String[] args) 8DyE
{ $YFn$.70\
new TestMethod(); GT`:3L
} }KJ/WyYW
} AuSL?kZ4|Y
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