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)); %y_pF?2@q
} 7N5M=f.DS(
for(int i=0;i<nEndPos.length-1;i++) p.MLKp-'
{ qUg/mdv&
nEndPos = nStartPos[i+1]; !Dc;R+Ir0!
} xVI"sBUu
nEndPos[nEndPos.length-1] = nFileLength; p_zVrlVb
} b9wC:NgQx
} *Br }U
VgY6M_V
qauvwAMuX
//启动子线程 QiqRx
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1 K^-tms
for(int i=0;i<nStartPos.length;i++) KB~`3Wj|Z
{ c8_,S[W
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )Fqtb;W=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "*c&[ALw
nStartPos,nEndPos,i); Dl\0xcE
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gH"aMEC
fileSplitterFetch.start(); R+U*]5~R
} fI.X5c>WK
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m<;MOS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); HFYe@2r
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", LR4W
nEndPos = " + nFileLength); sUkn.g!
// fileSplitterFetch[nPos.length-1].start(); *uxKI:rB:
:a=]<_*x
c*(=Glzn
//等待子线程结束 *Hv d
//int count = 0; PKGqu,J,
//是否结束while循环 qM>Dt
boolean breakWhile = false; Hg\H>Z
|\C.il7
0G'v4Vj0'
while(!bStop) 0N6 X;M{zh
{ l{kacfk#
write_nPos(); ,[_)BM
Utility.sleep(500); mkgL/h*
breakWhile = true; {=Py|N\\t
AO7X-,
27F:-C~.9
for(int i=0;i<nStartPos.length;i++) x;4m@)Mu
{ 5mZ9rLn
if(!fileSplitterFetch.bDownOver) k?Zcv*[)D+
{ *JWPt(bnI
breakWhile = false; N B8Yn\{B
break; 4i29nq^n
} %P*b&H^0
} !_&;#j](
if(breakWhile) v=IcVHuf
break; Kc3/*eu;
4LJOT_
Ml_!)b
//count++; EYZ,GT-I
//if(count>4) Hjy4tA7,l
// siteStop(); |A H@W#7j
} UwDoueXs
You~ 6d6Om
Hxj8cXUF|
System.err.println("文件下载结束！"); NL"w#kTc()
} 7P52r
catch(Exception e){e.printStackTrace ();} Bf,}mCq
} <9Ytv|t@0
1n$
y8|}bd<Sr
//获得文件长度 <FvljKuq+
public long getFileSize() (j}edRUnB
{ =?hbi]
int nFileLength = -1; KeC&a=HL
try{ ~HBx5Cpi
URL url = new URL(siteInfoBean.getSSiteURL()); wY7+E/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %S%0/
httpConnection.setRequestProperty("User-Agent","NetFox"); D._7)$d
V##TG0
qh wl
int responseCode=httpConnection.getResponseCode(); #XAH`L\
if(responseCode>=400) 3^F1hCB
{ 35SL*zS@-
processErrorCode(responseCode); wq#'o9s,
return -2; //-2 represent access is error `6G:<wX
} 5S #6{Y =
;;zd/n2b
,,Vuvn
String sHeader; %U&ztvR0C
TfA;4^
V8z*mnD
for(int i=1;;i++) I]N!cEr;@-
{ S)A;!}RK6
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2{)<Df@
//Utility.log(in.readLine()); R #m1Aa
sHeader=httpConnection.getHeaderFieldKey(i); Dl=vv9
if(sHeader!=null) A:,V)
{ P6 mDwR
if(sHeader.equals("Content-Length")) g_MxG!+(V
{ -"n8Wv
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); wW'.bqA
break; )$E'2|Gm/
} )Z@hk]@?_[
} S >\\n^SbT
else yI$MqR
break; X0%BE!
} #4?:4Im#
} *(Us:*$W.
catch(IOException e){e.printStackTrace ();} Zq\ p%AU9
catch(Exception e){e.printStackTrace ();} v|YJ2q?19
uGS^*W$
^p #bxN")
Utility.log(nFileLength); z%WOv~8~
R~XNF/QMl
ZY> u4v.
return nFileLength; R2nDK7j
} Ya,(J0l
))#_@CwRr
ZUeA&&{
//保存下载信息（文件指针位置） h>jp.%oOu
private void write_nPos() ^VlPnx8y=
{ +8V|
try{ 05vu{>
output = new DataOutputStream(new FileOutputStream(tmpFile)); \b|Q`)TK
output.writeInt(nStartPos.length); @NJJ
for(int i=0;i<nStartPos.length;i++) -;o`(3wZq
{ h5m6 )0"
// output.writeLong(nPos); T1~,.(#
output.writeLong(fileSplitterFetch.nStartPos); ?VT ]bxb
output.writeLong(fileSplitterFetch.nEndPos); Nx4X1j?-n
} 3`\)Qm
output.close(); H3"D$Nv
} |m>n4-5QL
catch(IOException e){e.printStackTrace ();} $^"_Fox]A\
catch(Exception e){e.printStackTrace ();} I~I$/j]e`
} <\S j5
lIF*$#`oh*
)v?-[ oR
//读取保存的下载信息（文件指针位置） 0_5j(
private void read_nPos() ) "Toh=x]
{ 4'-GcH
try{ Z8Il3b*)
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); lEv<n6:_
int nCount = input.readInt(); K=C).5=U
nStartPos = new long[nCount]; az ?2
nEndPos = new long[nCount]; l<mEGKB#
for(int i=0;i<nStartPos.length;i++) yS:1F PA$_
{ 6 bnuC
nStartPos = input.readLong(); VpMPTEZ*L
nEndPos = input.readLong(); We*)RXm%
} y:+s*x6Vg
input.close(); O6pL )6d
} ]w=6.LzO*
catch(IOException e){e.printStackTrace ();} +~A<&7[}
catch(Exception e){e.printStackTrace ();} l6Q75i)eF
} P>t[35/1
`FM^)(wT
MO$dim>
private void processErrorCode(int nErrorCode) t7p`A8&
{ ;hLne0|)}
System.err.println("Error Code : " + nErrorCode); '{:Yg3K
} *AU"FI>V
qm)KO 4
(g@e=m7Q
//停止文件下载 S qQqG3F
public void siteStop() 97um7n
{ <IBzh_
bStop = true; +$+'|w
for(int i=0;i<nStartPos.length;i++) X;ZR"YgT
fileSplitterFetch.splitterStop(); '?~k`zK
`2NL'O:
FQ?H%UcW
} gW6lMyiLb
} E+"INX7
//负责部分文件的抓取 R6)p4#|i
**FileSplitterFetch.java 5D]%E?ag
*/ "F|OJ@M
package NetFox; eF}Q8]da
FWdSpaas Q
z0HCmj9T
import java.io.*; Tc\^=e^N?
import java.net.*; *`);_EVc
GwwxSB&y
OV>T}Fq
public class FileSplitterFetch extends Thread { N"T~U\R
ez86+
; ZL<7tLDb
String sURL; //File URL Cz?N[dhh
long nStartPos; //File Snippet Start Position rQ*'2Zf'<
long nEndPos; //File Snippet End Position bg_Zf7{
int nThreadID; //Thread's ID YT,1E>rd
boolean bDownOver = false; //Downing is over Fm,A<+l@u
boolean bStop = false; //Stop identical n4k.tq
FileAccessI fileAccessI = null; //File Access interface 9T|7edl
F^T7u?^)
mbd
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >}u?{_s *0
{ xHykU;p@
this.sURL = sURL; tmK@Veb*a'
this.nStartPos = nStart; ,`/!0Wmt
this.nEndPos = nEnd; x;Dr40wD@y
nThreadID = id; YcRjbF,|6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 dm.?-u;C
} LD_aJ^(d
_\sm$ `q
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public void run() AUS?Pt[w
{ )J~Qx-jG
while(nStartPos < nEndPos && !bStop) y @Y@"y
{ *qY`MW
5[X^1
Zf]d'oW{/
try{ *[W!ng
URL url = new URL(sURL); >0@X^o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); t}nZrD
httpConnection.setRequestProperty("User-Agent","NetFox"); evg i\"
String sProperty = "bytes="+nStartPos+"-"; cy^6g?ew
httpConnection.setRequestProperty("RANGE",sProperty); O%(:8nIgZ
Utility.log(sProperty); [ "J
xE;fM\7pu
a2Q9tt>Q
InputStream input = httpConnection.getInputStream(); )dC%g=dtc
//logResponseHead(httpConnection); X[NsdD?w1+
R*Pfc91}
b0LQ$XM>8
byte[] b = new byte[1024]; dldM hT$
int nRead; C"IPCJYn
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) /kx:BoV
{ nN@8vivP%
nStartPos += fileAccessI.write(b,0,nRead); [^ 7^&/0
//if(nThreadID == 1) nF A7@hsm
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); QE<63|
} JsfbY^wz
4vBZb^W;9
2c8,H29
Utility.log("Thread " + nThreadID + " is over!"); ,E)bS7W
bDownOver = true; 6<]&T lS]
//nPos = fileAccessI.write (b,0,nRead); m>zUwGYEu
} vx!nC}f"k`
catch(Exception e){e.printStackTrace ();} QnaMjDh$6
} fcJ#\-+E
} cQ3Dk<GZ
qZ_^#%zO
z<^HohT
//打印回应的头信息 sHQe0"Eo
public void logResponseHead(HttpURLConnection con) ;M"hX
{ xOTm-Cm9L
for(int i=1;;i++) mqq~&nI
{ =B<g_9d4
String header=con.getHeaderFieldKey(i); iOki ZN+d>
if(header!=null) l<7 b
//responseHeaders.put(header,httpConnection.getHeaderField(header)); p+9vSM #
Utility.log(header+" : "+con.getHeaderField(header)); G;fP
else %I6iXq#
break; O%0G37h
} ##k=='dR
} [(#ncR8B
De4+4&
)2bPu[U
public void splitterStop() \8_&@uLm
{ <bGSr23*
bStop = true; Fo;xA
} bE]2:~
[0MVsc=
s'} oVx]
} n~K_|
$stJ+uh
+sgishqn9
/* ~5cLI;4h
**FileAccess.java x8zUGvtQ
*//文件访问(定位，写) 8#7z5:_
package NetFox; \n:'>:0X!
import java.io.*; ,Y9lp)w
||qsoF5B]
A5?[j QT0
public class FileAccessI implements Serializable{ @Cw<wrem
%G\rL.H|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 E>SnH
RandomAccessFile oSavedFile; \'E%ue_<9
long nPos; X<Vko^vlj
e[R364K
Xv=n+uo
public FileAccessI() throws IOException /pX\)wi
{ Z4E:Z}~''
this("",0); \7gLk:
} g-Z>1V
hua{g_
hQ8/-#LO_
public FileAccessI(String sName,long nPos) throws IOException '>2xP<ct!&
{ R2t5T-8`c
oSavedFile = new RandomAccessFile(sName,"rw"); ,Qj7wFZ
this.nPos = nPos; 9<\wa/#
oSavedFile.seek(nPos); 3VALrb;
} KQQR"[z&V
<P}{0Y~@*W
-br/
public synchronized int write(byte[] b,int nStart,int nLen) [y=k}W}z
{ [^~Fu9+"
int n = -1; e~nmIy
try{ 9s5CqB
oSavedFile.write(b,nStart,nLen); ~~:i+-[
n = nLen; n1.]5c3p
} cKFzn+
catch(IOException e) J<u,Y= -~
{ q=UKL`;C}U
e.printStackTrace (); Mq6.!j
} [S-NGip
& UL(r
(#LV*&K%IC
return n; waO*CjxE:
} wgzjuTqwBF
WR gAc%
Hz%#&E
} )k <ON~x
jJ|u!a
r?[PIf
/* 1ciP+->$
**SiteInfoBean.java IkL|bV3E0
*/ Aj SIM.
package NetFox; pbR84g^p.S
6&$z!60
yi r#G""7
public class SiteInfoBean { WLv( K_3Y
.+|G`*1<i
9V[|_
private String sSiteURL; //Site's URL a}0\kDe
private String sFilePath; //Saved File's Path L7%Dc2{^(
private String sFileName; //Saved File's Name WTSY:kvcCY
private int nSplitter; //Count of Splited Downloading File Y-gjX$qGo
}bAd@a9>3
j}#48{
public SiteInfoBean() #B;`T[
{//nSplitter的缺省值为5 Uj1^?d+b
//default value of nSplitter is 5 dkLc"$(O
this("","","",5); 9%>H}7=
} X./8 PK?&
-`&4>\o2Lx
P/,7CfyPd
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4US8B=jk
{ oT5?*3f
sSiteURL= sURL; fw|r{#d
sFilePath = sPath; T{{J' _s5L
sFileName = sName; \02j~r`o
this.nSplitter = nSpiltter; IP-CN
=@G#c5H*
2RT9Q!BX{
} UI_|VU>J
J &u&G7#S
zf5s\w.4
public String getSSiteURL() B`T|M$Ug
{ 'g|%Ro/
return sSiteURL; C>:F4"0
} =LZj6'
F,%qG,
](x4q
public void setSSiteURL(String value) ` {k>I^Pg
{ w`c9_V
sSiteURL = value; `0=0IPVd
} j/#kO?
z%`Tf&UL
slDxsb
public String getSFilePath() [j 'Ogm7"
{ !})/x~~e
return sFilePath; gTH1FR8$y
} "5synfO
67<zBw2
^G~W}z?-
public void setSFilePath(String value) (X)$8y
{ nAoGG0$5
sFilePath = value; {QM;%f
} dt',)i8D
Gyjx:EM
Y H 2iV
public String getSFileName() SL hki)|
{ awHfd5nRS
return sFileName; GH7{_@pv8
} v|?hc'Fj
HsR#dp+s~
5caYA&R
public void setSFileName(String value) bv\V>s
{ >m:.5][yu
sFileName = value; _-%ay
} "f!*%SR: 1
d;mQ=k 1
6x]|IWvW
public int getNSplitter() F}H!vh[
{ j /)cdP
return nSplitter; 7v?tSob:b
} i>ORCOOU
\#LKsQa
cuq7eMG6z
public void setNSplitter(int nCount) :54|Z5h|
{ g"(N_sv?
nSplitter = nCount; pr;<n\Y{
} #xW%RF
} ~1|sf8
0WF(Ga/o
P^rSpS9
/* yC+N18y?
**Utility.java Ef%8+_
*/ ;cp-jY_U
package NetFox; zHb<YpU
_N/]&|.. !
^}/YGAA
public class Utility { GVn9=[r
_9!Ru!u~
RVI],O
public Utility() ,yV pB)IQ
{ )@R:$l86
_j%Rm:m;<
mNb+V/*x3
} Mh~T.;f.qq
ei\X/Z*q%P
//线程睡眠 d57(#)`
public static void sleep(int nSecond) aj(M{gFq~
{ PDD` eK}Fj
try{ OR?8F5o?p
Thread.sleep(nSecond); ~@'|R%jJ
} /jj@ =H
catch(Exception e) GExG1n-
{ UwE^ij
e.printStackTrace (); #:s'&.6
} +Kf::[wP7
} ^1*p]j(
/23v]HEPy
//日志 *,'"\n
public static void log(String sMsg) !Id F6 %
{ e}K;5o=I
System.err.println(sMsg); "K\Rq+si
} #e8CuS
QQ!,W':
qZ1fQN1yG
public static void log(int sMsg) E>4 \9
{ @kqy!5)K
System.err.println(sMsg); brTB /(E
} 6PPvfD^
} ImF/RKI~ "
~)ByARao=
UI8M<
/* B"Fg`s+]U
**TestMethod.java M2oKLRt)L
*/ VFYJXR{
package NetFox; 97Q!Rot
0;XnNz3&
mS%D" e
public class TestMethod { j;+nnpg
.0a$E`V=D
.5I1wRN49
public TestMethod() P,>#
{ ///xx/weblogic60b2_win.exe Y:byb68
try{ +:Y6O'h.
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :^ cA\2=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }NYsKu_cM
SiteFileFetch fileFetch = new SiteFileFetch(bean); kwyvd`J8
fileFetch.start(); FijzO
} ,>~92
catch(Exception e){e.printStackTrace ();} }2h~o~
sxuYwQ
/Wj9Stj5
} 9wI1/>
`Y(/G"]
`U;4O)`n
public static void main(String[] args) :|fzGf
{ Qb SX'mx<
new TestMethod(); \ (X~Z
} -Ol/r=/&
} *.i`hfRc
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