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)); KT~J@];Fb
} %Ez%pT0TQ#
for(int i=0;i<nEndPos.length-1;i++) O|m-Uz"+
{ 3.U5Each-
nEndPos = nStartPos[i+1]; A\ds0dUE
} !;.i#c_u
nEndPos[nEndPos.length-1] = nFileLength; } R!-*Wk
} 8fFURk
} 9_V'P]@
..V6U"/
]Cnj=\'
//启动子线程 9-[g/qrF
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; nF0$
for(int i=0;i<nStartPos.length;i++) 8~AO~
{ $J"}7+
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jo{[*]Oa
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~j}di^<{
nStartPos,nEndPos,i); dy N`9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \2 &)b
fileSplitterFetch.start(); {c`kC]9
} }C!N$8d,
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), lfG]^id'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); tX$%*Uy
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #X'!wr|-
nEndPos = " + nFileLength); P0uUVU=B|
// fileSplitterFetch[nPos.length-1].start(); Sq8`)$\
EzqYHY+_r
zm4Okg)w@
//等待子线程结束 li;Np5P
//int count = 0; +RQlMAB
//是否结束while循环 ~F~g$E2 }
boolean breakWhile = false; "gjy+eosY
cJj4qXF
g+;m?VJ
while(!bStop) ' Z:FGSwT
{ fQRGz\r*k
write_nPos(); XSC._)ztEE
Utility.sleep(500); o#gb+[
breakWhile = true; 'qwFVP
fC+<n{"C
M%pxv6?""{
for(int i=0;i<nStartPos.length;i++) eE5U|y)_
{ }eb}oK
if(!fileSplitterFetch.bDownOver) z40uY]Ck
{ +168!Jw;
breakWhile = false; W(a31d
break; `VY -3
} bDVz+*bU}
} (Em^qN
if(breakWhile) 0G ^73Z
break; |S[Gg
LPX@oha
{;1Mud
//count++; 4<fKB&
//if(count>4) LnP={s
// siteStop(); 0*S]m5#;
} Gh}sk-Xk=
IOmQ1X7,
QxG:NN;jW
System.err.println("文件下载结束！"); }wRHNBaEB
} pYIm43r H
catch(Exception e){e.printStackTrace ();} VSP6osX{
} Wcd;B7OH
4^\5]d!
U|VFzpJ
//获得文件长度 rdZk2\<
public long getFileSize() )!J0e-T-8O
{ $K>'aI;|
int nFileLength = -1; &Iv3_T<AF
try{ Uu ~BErEC
URL url = new URL(siteInfoBean.getSSiteURL()); SE/GT:}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *-"DZ
httpConnection.setRequestProperty("User-Agent","NetFox"); Wm\HZ9PN
unu%\f>^4
$}RBK'cr}
int responseCode=httpConnection.getResponseCode(); gBb+Q,
if(responseCode>=400) 3*C9;Q}
{ 8$9<z
processErrorCode(responseCode); TOmq2*,/
return -2; //-2 represent access is error Bc3(xI'>J
} |2w,Np-
78&(>8@m
5/4N Y
String sHeader; N9@@n:JT
uLXMEx<^
^x(BZolkm
for(int i=1;;i++) E-jL"H*
{ V("@z<b|
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); gFlUMfKh
//Utility.log(in.readLine()); `Mx&,;x
sHeader=httpConnection.getHeaderFieldKey(i); at"-X?`d
if(sHeader!=null) e]F4w(*=
{ <nDuN*|
if(sHeader.equals("Content-Length")) @H[)U/.
{ .`qw8e}y#'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x&>zD0\ :\
break; Q${0(#Nu
} =yo?]ZS
} M ^gva?{
else <Vucr
break; JwEQR
} @%Y$@Qb{
} }jTCzqHW]
catch(IOException e){e.printStackTrace ();} uFPJ}m[>5
catch(Exception e){e.printStackTrace ();} 0\XG;KA
T=Q"|S]V
Mg3>/!
Utility.log(nFileLength); 2;X{ZLo
b.HfxYt(
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return nFileLength; D >ax<t1K
} Hw[(v[v
1N8gH&oF
TY,5]*86I&
//保存下载信息（文件指针位置） }i,LP1R
private void write_nPos() o"h*@.
{ $M%<i~VXe&
try{ W~(4t:hp
output = new DataOutputStream(new FileOutputStream(tmpFile)); ( -^-
output.writeInt(nStartPos.length); b {fZU?o
for(int i=0;i<nStartPos.length;i++) cb|cYCo5
{ w0W9N%f#=
// output.writeLong(nPos); pxC:VJ;
output.writeLong(fileSplitterFetch.nStartPos); 3i1e1Lj1
output.writeLong(fileSplitterFetch.nEndPos); l0AVyA4RFV
} Qb "\j
output.close(); eru2.(1
} cTlitf9
catch(IOException e){e.printStackTrace ();} @~WSWlQW
catch(Exception e){e.printStackTrace ();} {[B^~Y>Lr
} g=iPv3MG
]M2<b:yo
2e~ud9,
//读取保存的下载信息（文件指针位置） {|dU|h
private void read_nPos() -jN:~.
{ J*V@huF
try{ rqa?A}'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); qu>5 rg-
int nCount = input.readInt(); EPO*{bN7O
nStartPos = new long[nCount]; Tgxxm
nEndPos = new long[nCount]; $'m&RzZ
for(int i=0;i<nStartPos.length;i++) %K@s0uQ
{ bWp40&vx
nStartPos = input.readLong(); ynkPI6o
nEndPos = input.readLong(); J*4byu|
} }M_Yn0(3
input.close(); #"PI%&
} (H=7(
catch(IOException e){e.printStackTrace ();} z +NxO!y
catch(Exception e){e.printStackTrace ();} oEfy{54
} @|A wT
WEX6I16
:.xdG>\n3
private void processErrorCode(int nErrorCode) !a %6nBo
{ s Yp?V\Y"
System.err.println("Error Code : " + nErrorCode); Ekq&.qjYG"
} /eFudMl
2RW^Nqc9
Y<1]{4Wt
//停止文件下载 ';T=kS<^_
public void siteStop() #p<1@,
{ uLr9*nxd
bStop = true; SU.9;I !
for(int i=0;i<nStartPos.length;i++) `8 Q3=^)3
fileSplitterFetch.splitterStop(); gD$bn=
x!)[l;
"v%|&@
} R 2.y=P8N
} ^uG^XY&ItC
//负责部分文件的抓取 <qGVOAnz+
**FileSplitterFetch.java ^5BLuN6
*/ o*\cV6
package NetFox; 'VH%cz*
mn5mdrv3WZ
0W}iKT[Z
import java.io.*; Y@&1[Z
import java.net.*; {R5{v6m_
s>d /9 b
X9:4oMux7
public class FileSplitterFetch extends Thread { g7>p,
8Xo`S<8VS
1w30Vj2<
String sURL; //File URL Z.!tp
long nStartPos; //File Snippet Start Position CqF=5z:A
long nEndPos; //File Snippet End Position ]mED3#
int nThreadID; //Thread's ID 4JOw@/nE
boolean bDownOver = false; //Downing is over ZW+[f$X
boolean bStop = false; //Stop identical <4DSk9/
FileAccessI fileAccessI = null; //File Access interface g)o?nAr
,B^NH7A:
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |{)SLvlJl
{ :)cn&'l(S
this.sURL = sURL; P:`tL)W_
this.nStartPos = nStart; e+_~a8 -|
this.nEndPos = nEnd; ^F}HWpF_
nThreadID = id; FNQR sNi
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6[iuCMOZ
} NTj:+z0
,7wxVR%Ys
KN41kkN
public void run() aWtyY[=
{ SL( WE=H
while(nStartPos < nEndPos && !bStop) 627xR$U~
{ sE,Q:@H5
-~wGJM VA
]yR0"<W^xO
try{ 'Dh+v3O
URL url = new URL(sURL); N sUFM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w-[A"M]I
httpConnection.setRequestProperty("User-Agent","NetFox"); @(;zU~l/
String sProperty = "bytes="+nStartPos+"-"; yP&SA+
httpConnection.setRequestProperty("RANGE",sProperty); GQU9UXe
Utility.log(sProperty); /.?m9O^ F
DA0{s
$}9.4`F>
InputStream input = httpConnection.getInputStream(); K5oVB,z)
//logResponseHead(httpConnection); m{~p(sQL
&s]wf
R^nkcLFb/q
byte[] b = new byte[1024]; 9)_fH6r
int nRead; =|@%5&.P
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )2 Omsh
{ ^5"2s:vP
nStartPos += fileAccessI.write(b,0,nRead); n$z}DE5 #
//if(nThreadID == 1) C>1fL6ct
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M*& tVG
} :tc]@0+
&7gL&AY8
'Z<V(;W
Utility.log("Thread " + nThreadID + " is over!"); .:<-E%
bDownOver = true; upD2vtU
//nPos = fileAccessI.write (b,0,nRead); Z$8X1(o
} _A8x{[$
catch(Exception e){e.printStackTrace ();} aN87^[
} 3jH8pO^
} 09_L^'`
|'C{nTX
6?"k&O
//打印回应的头信息 Q t!X<.
public void logResponseHead(HttpURLConnection con) evbqBb21b
{ 4bT21J37
for(int i=1;;i++) (l|:$%[0
{ ywPFL/@
String header=con.getHeaderFieldKey(i); OS X5S:XS
if(header!=null) %*>ee[^L ,
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \~3g*V
Utility.log(header+" : "+con.getHeaderField(header)); jz\LI
else kQr\ktN\
break; K):MT[/"
} SBj9sFZ
} U\_-GS;1
$m.e}`7SF!
N*k`'T
public void splitterStop() z[7j`J|Kk
{ "R"7'sJMI
bStop = true; S\qYw(G
} HJ&|&tT
UR/lM,N;
Jgf73IX[
} #$<7
yK1Z&7>J>
]5!}S-uJq
/* %T.4Aj
**FileAccess.java ~"<AYJlO
*//文件访问(定位，写) pH?tr
package NetFox; MZpG1
import java.io.*; ERql^Yr
7~t,Pt)
sT.:"Pj$
public class FileAccessI implements Serializable{ H;QE',a9+i
AfzE0mBW
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 S{v [65
RandomAccessFile oSavedFile; |@}Yady@C
long nPos; Ha U6`IP
ur'a{BI2R
'>GZB
public FileAccessI() throws IOException L_>j SP
{ C *\ =Q
this("",0); Ab]`*h\U
} wKjL}1.k
{=(GY@yU/
p8%/T>hK
public FileAccessI(String sName,long nPos) throws IOException W!$aK)]4u
{ tMWDKatb
oSavedFile = new RandomAccessFile(sName,"rw"); \6UK:'5{
this.nPos = nPos; l8"
oSavedFile.seek(nPos); NH?q/4=I0W
} ?a8 o.&`l
Kr$ w"]
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public synchronized int write(byte[] b,int nStart,int nLen) Us4ijR d
{ vgfLI}|5
int n = -1; =:T pH>f*
try{ "?I]h
oSavedFile.write(b,nStart,nLen); (GLd"Zq
n = nLen; ryd*Ha">I
} {x3"/sF
catch(IOException e) V!eq)L
{ @`qhQ
e.printStackTrace (); xt! DS0|*Y
} }Q7~tu
Et\z^y
e 1W9Z $m
return n; F_m[EB
} ])dq4\Bw
Up61Xn
&ukYTDM
} ZDVz+L|p
83"Vh$&
.%{3#\
/* a$f$CjQ
**SiteInfoBean.java Kh)SgJ3B@
*/ <NV[8B#k]
package NetFox; 9{gY|2R_
l]BIFZ~
]!yuD/4A
public class SiteInfoBean { 6 ufF34tA
aP}kl[W
f'hrS}e
private String sSiteURL; //Site's URL }i32
private String sFilePath; //Saved File's Path Pt/dH+r`%
private String sFileName; //Saved File's Name 5ua`5Hb;
private int nSplitter; //Count of Splited Downloading File 7J~usF>A
MHs2UN
M.|@|If4?
public SiteInfoBean() ?Y:>Ouv*z'
{//nSplitter的缺省值为5 3},0b8};
//default value of nSplitter is 5 58x=CN\QU
this("","","",5); HZp}<7NR(7
} #nQZ/[|
ac8+?FpK #
+|#lUXC
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !d@qT.
{ ),#%jc2_^
sSiteURL= sURL; <ID/\Qx`q
sFilePath = sPath; MfJ;":]O!
sFileName = sName; 5PY,}1`
this.nSplitter = nSpiltter; FLT4:B7
;pK/t=$
#KC& ct
} .;ptgX
0PiD<*EA
+!dWQ=W
public String getSSiteURL() Qh4@Nl#Ncf
{ ~x:\xQti
return sSiteURL; Ks|qJ3;
} +Y7"!wYR>
#S?xRqkc
('H[[YODh
public void setSSiteURL(String value) ~j%g?;#*
{ 5)g6yV'
sSiteURL = value; :VP*\K/:
} B d#D*"gx
[,A*nU$
^Ht!~So
public String getSFilePath() *D&(6$[^
{ aS ]bTYJ'
return sFilePath; z8HOig?
} ,>H(l$n
gi26Dtk(h
X?m"86L
public void setSFilePath(String value) V)[ta`9
{ &L&6y()G
sFilePath = value; J$'Q3k
} <m;idfn
)tB:g.2k
V`F]L^m=L
public String getSFileName() C%hMh/Li;
{ :A+nmz!z
return sFileName; ^FaBaDcnl
} YNEPu:5J
SFKfsb!C
e^;<T9Esr
public void setSFileName(String value) $)UMRG
{ /oA=6N#j
sFileName = value; mmE!!J`B
} DG2CpR)S
vuL;P"F4&
g^ @9SU
public int getNSplitter() nnP]x [
{ ^[]q/v'3m!
return nSplitter; CC?L~/gPN
} {s]yP_
}/dGC;p"
r]GG9si
public void setNSplitter(int nCount) ]r]=Q"/5
{ 2vb{PQ
nSplitter = nCount; >_R,^iH"
} ^T(v4'7
} Dt)O60X3>
HF(pC7/a:
Fjq~^_8
/* SSoD}N
**Utility.java o75Hit
*/ 0?x9.]
package NetFox; :Z(w,
oqLM-=0<}
dRl*rP/
public class Utility { ,hMdxZJd
9j[lr${A
dfo_R
public Utility() w(>mP9Cb
{ 33O O%rWi
y7iHB k"^:
$2tPqZ>
} O,$ ?Pj6
bl/tl_.p00
//线程睡眠 @m#1[n;
public static void sleep(int nSecond) n'WhCrW
{ _9y
try{ hn$l<8=Q_
Thread.sleep(nSecond); -w>2!@8
} ;M)l7f
catch(Exception e) |j?iD
{ M/!5r
e.printStackTrace (); aPR0DZ@
} \=3fO(
} _'CYS3-P3
J5i$D0K[
//日志 #YABbwH
public static void log(String sMsg) Ub>Pl,~'
{ l_?r#Qc7
System.err.println(sMsg); 0!Zp4>l\Z
} 0uw3[,I
pwu8LQ3b{O
!YM;5vte+
public static void log(int sMsg) N;\G=q] 9
{ 8y9`xRy
System.err.println(sMsg); Cob<N'.
} aPELAU-
} ceKR?%8s
APne!
D@-'<0=
/* ,McwPHEMB
**TestMethod.java VG)Y$S8.>
*/ 8w 2$H
package NetFox; 3#d?
'[T#d!T
JDa=+\_
public class TestMethod { |._9;T-Yde
cH==OM7&-
KNI* :
public TestMethod() ?3=D-Xrb
{ ///xx/weblogic60b2_win.exe GS<aXhk
try{ 4>JDo,AWy
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); D&)w =qIu
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); a>_Cxsb&`
SiteFileFetch fileFetch = new SiteFileFetch(bean); =|Q7k+b
fileFetch.start(); F:3*i^ L
} TB oN8cB}
catch(Exception e){e.printStackTrace ();} ~|FKl%
K3CTxU(
?zS t
} dg(fD>+
9f wFSJx
TgDx3U[
public static void main(String[] args) /:<.Cn>-
{ h2Kx
new TestMethod(); /4Df 'd
} ZysZS%
} H@j D%
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