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 [M,]?
} 6863xOv{T
for(int i=0;i<nEndPos.length-1;i++) Gt1U!dP
{ M}a6Vu9
nEndPos = nStartPos[i+1]; pmM9,6P4@
} >z03{=sAN
nEndPos[nEndPos.length-1] = nFileLength; W!X@
} dM5-;
} 7v kL1IA
bOB\--:]
CAJ'zA|o
//启动子线程 9Na$W:P c
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; NUZl`fu1Z4
for(int i=0;i<nStartPos.length;i++) M{@(G5
{ Z r8*et
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hrn+UL:d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^c<Ve'-
nStartPos,nEndPos,i); ]'}L 1r
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pkzaNY/q
fileSplitterFetch.start(); UpG~[u)%@
} &HW9Jn
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %A`+WYeuX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ![1rzQvGDb
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ]`K2N
nEndPos = " + nFileLength); X, n:,'
// fileSplitterFetch[nPos.length-1].start(); Oz95
Nc`L;CP
%Zi} MPx
//等待子线程结束 M-71 1|eGI
//int count = 0; tA;}h7/Lc~
//是否结束while循环 [~HN<>L@C
boolean breakWhile = false; ,prf;|e?
>Ry01G]_/h
k:;r2f
while(!bStop) 2ESo2
{ r;{.%s7
write_nPos(); C_Dn{
Utility.sleep(500); h0$iOE
breakWhile = true; K-4PI+qQ\
t_^4`dW`
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for(int i=0;i<nStartPos.length;i++) Hka2
{ mt .sucT
if(!fileSplitterFetch.bDownOver) 80I#TA6C
{ rp$'L7lrX
breakWhile = false; >6T8^Nt
break; J5qZFD
} LoV<:|GTI
} ;uJMG
if(breakWhile) ?4,T}@P
break; j%kncGS
8LKiS
V0@=^Bls
//count++; L0,'mS
//if(count>4) vP&(-a
// siteStop(); *@5@,=d
} a(nlTMfu
$FVNCFN%
e ,(mR+a8
System.err.println("文件下载结束！"); dPlV>IM$z
} "jZ-,P=
catch(Exception e){e.printStackTrace ();} lA]8&+,ZM
} tmqOJ
N8jIMb'<
(QEG4&9
//获得文件长度 Y2AJ+ |
public long getFileSize() 4(+PD&_J
{ Z@HEj_n
int nFileLength = -1; B\~}3!j
try{ -@'FW*b
URL url = new URL(siteInfoBean.getSSiteURL()); K;?+8(H
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); XFl6M~ c
httpConnection.setRequestProperty("User-Agent","NetFox"); 7!1S)dup
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?<!|
int responseCode=httpConnection.getResponseCode(); )lkjqFQ(
if(responseCode>=400) kiEa<-]
{ J.a]K[ci
processErrorCode(responseCode); $'vU2L
return -2; //-2 represent access is error >4TO=i
} /~1+i'7V.,
=_CzH(=f#
dtDFoETz
String sHeader; Wtnfa{gP%
I9^x,F"E]
vx =&QavL
for(int i=1;;i++) -"x$ZnHU
{ )%TmAaj9d
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5xiEPh
//Utility.log(in.readLine()); $4\j]RE!
sHeader=httpConnection.getHeaderFieldKey(i); _`X:jj>
if(sHeader!=null) tQVVhXQ7
{ >P(.:_^p
if(sHeader.equals("Content-Length")) mpyt5#f
{ kJU2C=m@e2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); X}]-*T|a
break; `[A];]
} bA 2pbjg=
} gYj'(jB
else / {%%"j
break; sW$XH1Uf#
} Om&Dw|xG8
} \V:^h[ad
catch(IOException e){e.printStackTrace ();} #yen8SskB
catch(Exception e){e.printStackTrace ();} ]e3Ax(i)
e20-h3h+
9WHddDA
Utility.log(nFileLength); Gj*9~*xm(
kAx4fE[c
bt *k.=p
return nFileLength; ICCc./l|
} reVgqYp{{-
~[: 2I
k)u[0}
//保存下载信息（文件指针位置） GbyJ:
private void write_nPos() & kIFcd@
{ YIE<pX4Q7)
try{ 6*?F@D2&
output = new DataOutputStream(new FileOutputStream(tmpFile)); 13PS2
output.writeInt(nStartPos.length); i4Jc.8^9$
for(int i=0;i<nStartPos.length;i++) c> af
{ =41xkAMnk
// output.writeLong(nPos); 9L9sqZUB
output.writeLong(fileSplitterFetch.nStartPos); !k%#R4*>
output.writeLong(fileSplitterFetch.nEndPos); [lAp62i5
} ijcm2FJcG
output.close(); n%-0V>
} g`^x@rj`E
catch(IOException e){e.printStackTrace ();} _@g;8CA
catch(Exception e){e.printStackTrace ();} zT/\Cj68
} l2d{ 73h
d _ e WcI
wzaV;ac4K
//读取保存的下载信息（文件指针位置） *"kM{*3:v
private void read_nPos() VpUAeWb
{ \jA~9
try{ >7r!~+B"9'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /(T?j!nPE
int nCount = input.readInt(); X8|EHb<
nStartPos = new long[nCount]; =xrv~
nEndPos = new long[nCount]; z2c6T.1M
for(int i=0;i<nStartPos.length;i++) Je@v8{][|
{ F?cK-.
nStartPos = input.readLong(); 7rA;3?p)
nEndPos = input.readLong(); eQ"E
} }%z
input.close(); {!`4iiF
} $cR{o#
catch(IOException e){e.printStackTrace ();} C?Ucu]cW
catch(Exception e){e.printStackTrace ();} nm+s{
} F"<vaqT2
;]fs'LH
/>Nt[o[r
private void processErrorCode(int nErrorCode) Zov~B-Of:
{ {T8Kk)L
System.err.println("Error Code : " + nErrorCode); q =Il|Nb>
} Ug`djIL
ExM,g'7
jIF |P-
//停止文件下载 |'.
public void siteStop() HqTjl4ai
{ 6Iw\c
bStop = true; .KC++\{HE
for(int i=0;i<nStartPos.length;i++) |M_UQQAB|
fileSplitterFetch.splitterStop(); 4sM.C9W
KF/-wZ"1s
kR9-8I{J
} 7Qsgys#/=
} xCKRxF
//负责部分文件的抓取 fX)#=c|5
**FileSplitterFetch.java 6r_)sHf
*/ *j-aXN/$
package NetFox; &/b~k3{M_
2JFpZU"1
8V(pugJ
import java.io.*; uGt-l4
import java.net.*; njw|JnDv
akT6^cP^
y==CTY@
public class FileSplitterFetch extends Thread { fT{Yg /j
pNIf=lA
go"Hf_
String sURL; //File URL O~QB!<Q+
long nStartPos; //File Snippet Start Position s@DLt+ O5
long nEndPos; //File Snippet End Position ;>YzEo
int nThreadID; //Thread's ID 03(4 x'z
boolean bDownOver = false; //Downing is over wf$s*|z
boolean bStop = false; //Stop identical G9:l'\
FileAccessI fileAccessI = null; //File Access interface Wm3X[?V
EIQ p>|5
@o6L6Y0Naa
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4e1Y/ Xq`
{ 9K&:V(gmw
this.sURL = sURL; HKr Mim-
this.nStartPos = nStart; %#}Zy
this.nEndPos = nEnd; x;')9/3
nThreadID = id; <9%R\_@$H
fileAccessI = new FileAccessI(sName,nStartPos);//定位 nLiY%x`S
} ,: ->ErP
N36_C;K-z
2|bn(QYz
public void run() m9A!D
{ H4JTGt1"
while(nStartPos < nEndPos && !bStop) +U.I( 83F
{ 9I/N4sou
!YJs]_Wr
Ki~1qu:
try{ O#u=c1 ?:
URL url = new URL(sURL); .}`Ix'.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FEVlZ<PW3I
httpConnection.setRequestProperty("User-Agent","NetFox"); PY0j9$i?
String sProperty = "bytes="+nStartPos+"-"; O<e{
httpConnection.setRequestProperty("RANGE",sProperty); D)'bH5
Utility.log(sProperty); -S+zmo8
-Vhw^T1iV
2T TdH)
InputStream input = httpConnection.getInputStream(); :Lug7bUVD
//logResponseHead(httpConnection); Fr$5RAyg
evJ.<{M
v<:R#
byte[] b = new byte[1024]; +&"zU GTIc
int nRead; -B\HI*u
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) T"}vAG( .O
{ ++#5
nStartPos += fileAccessI.write(b,0,nRead); w8D"CwS1Rx
//if(nThreadID == 1) Z87|Zl
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D#/Bx[
} hDq`Z$_+KX
@Pzu^
o7LuKRl
Utility.log("Thread " + nThreadID + " is over!"); 5Zva:
bDownOver = true; f0aKlhEC
//nPos = fileAccessI.write (b,0,nRead); Dl8;$~
} .@Dxp]/B}
catch(Exception e){e.printStackTrace ();} 8Dm%@*B^b
} 9]wN Bd
} [R7Y}k:9U
")HFYqP>9
-8rjgB~."/
//打印回应的头信息 )Iq<+IJ
public void logResponseHead(HttpURLConnection con) Nl(3Xqov
{ MO <3"@/,
for(int i=1;;i++) QS]1daMIK<
{ Sa`Xf\
String header=con.getHeaderFieldKey(i); 5RpjN: 3
if(header!=null) we?76t:-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {3{"8-18
Utility.log(header+" : "+con.getHeaderField(header)); oD1/{dRzj
else fLm*1S|%\
break; VD]zz ^
} yD6[\'%
} {LQ#y/H?
}:*]aL<7_
,tJ" 5O3-
public void splitterStop() nSAdCJ;4
{ -n<pPau2
bStop = true; Jl9k``r*
} ([LSsZ]sj
;H.^i|_/
2q4<t:!
} !V g`
=;&yd';k
P{+T<bk|
/* 9dUravC7
**FileAccess.java Nf"r4%M<6
*//文件访问(定位，写) `o8/(`a
package NetFox; FXN/Yq
import java.io.*; [>%xd)8.c
A/KJqiag
QTXt8I
public class FileAccessI implements Serializable{ :Ab%g-
DOJN2{IP
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9!}8UALD
RandomAccessFile oSavedFile; B%76rEpvW;
long nPos; PFne+T!2F
nd1+"-,q
C$D-Pt"+
public FileAccessI() throws IOException es&vMY
{ 5Qn '
this("",0); Midy"
} CtAwBQO
~W+kiTsD?
n}G|/v<
public FileAccessI(String sName,long nPos) throws IOException =U|.^5sa#
{ 9:1Q1,-i!-
oSavedFile = new RandomAccessFile(sName,"rw"); K&70{r
this.nPos = nPos; {~sDYRX
oSavedFile.seek(nPos); t@N=kV
} d>fkA0G/9!
ime\f*Fg
[@b&? b~K
public synchronized int write(byte[] b,int nStart,int nLen) OFv%B/O
{ IS 2^g>T#1
int n = -1; h=kh@},
try{ F,dx2ZPIs?
oSavedFile.write(b,nStart,nLen); 5$&%re!{Z
n = nLen; L3--r
} sOJQ,"sB
catch(IOException e) D.Q=]jOs
{ Dg?70v<a
e.printStackTrace (); *q".-u!D[
} }\#Rot>Y
"C19b:4H
[uq$5u
return n; *ikc]wQr$
} gy0haW
FUOI3
\r,Q1n?7
} "a"]o
k |%B?\m
%S nd\
/* ;z:UN}
**SiteInfoBean.java ?5cI'
*/ M8Z2Pg\0
package NetFox; 0[*qY@m:Z
D'A/wG
;b(p=\i
public class SiteInfoBean { *"n vX2iz
/)(#{i*
I_rO!
private String sSiteURL; //Site's URL h{p=WWK
private String sFilePath; //Saved File's Path q51Uf_\/
private String sFileName; //Saved File's Name R>"OXFaE
private int nSplitter; //Count of Splited Downloading File q**G(}K
x{c/$+Z[
i35=Y~P-
public SiteInfoBean() `Ru3L#@
{//nSplitter的缺省值为5 '-b*EZU8t
//default value of nSplitter is 5 5~WGZc
this("","","",5); !0C^TCuG
} ixQJ[fH10
,NVsn
(tGY%oT"
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) c#]q^L\x
{ 09kt[
sSiteURL= sURL; }HYjA4o\A
sFilePath = sPath; {=-\|(Bx
sFileName = sName; '@CR\5 @
this.nSplitter = nSpiltter; ^:* 1d \
ZRVT2VfN
/'DsB%7g
} z,bQQ;z9
Eb>78k(3I)
m[@Vf9
public String getSSiteURL() fpN- o
{ aKJQm'9Ks
return sSiteURL; !o+_T?
} V-r3-b
$aPfGZ<i
XNb ZNaAd
public void setSSiteURL(String value) GMZv RAui
{ h=_0+\%
sSiteURL = value; ]B]*/
} qTo-pAG`
u=/CRjot
+@K09ge
public String getSFilePath() ZzBQe
{ ^~HQC*
return sFilePath; ;/*6U
} v[n7"
g}U3y'
T=:]]nf?M
public void setSFilePath(String value) -}6xoF?
{ 0W()lQ
sFilePath = value; ed_FiQd
} 3 Lsj}p
}Lw>I94e
V)i5=bHC
public String getSFileName() ulJX1I=|p
{ a9?y`{%L
return sFileName; KyO8A2'U
} !!nuAQ"E[
q;wLa#4)J
S"hTE7`
public void setSFileName(String value) iIGbHn,/
{ zPKr/
sFileName = value; $CE[MZ&S
} !HJ$UG/\
J!*/a'Cv
LR,7,DH$9'
public int getNSplitter() 35x 0T/8
{ DK&h eVIoZ
return nSplitter; }V|{lvt.
} 45H!;Qsk
|uH%6&\
vkRi5!bR
public void setNSplitter(int nCount) a%Jx `hx
{ 5')8r';,
nSplitter = nCount; *$M'`vj:
} .~gl19#:T
} *X38{rj
g3%t8O/M
9OfFM9(:
/* /+3a n9h
**Utility.java \M/6m^zS
*/ 3?s ?XAh
package NetFox; 2`=6%s
4E:bp
ksjUr1o
public class Utility { 9(!]NNf!
>uI$^y1D
mty1p'^KQ
public Utility() ,A5)<}
{ GW2')}g
XO F1c3'H
8S;CFyT\n
} ,goBq3[%?
n!He&
//线程睡眠 )DUL)S
public static void sleep(int nSecond) mi2o1"Jd$`
{ ?&l)W~S
try{ ~tGCLf]c\
Thread.sleep(nSecond); ]wuy_+$
} n`;R pr&
catch(Exception e) zSjgx_#U
{ rFL$QC2
e.printStackTrace (); XvSIWs
} 9|S`ub'
} RwTzz] M
1;W=!Fx
//日志 e"+dTq8W
public static void log(String sMsg) q?~Rnv
{ M}.b" ljZ
System.err.println(sMsg); <kD#SV%"
} -0,4egj3
M'1HA
D(r:}pyU
public static void log(int sMsg) -'C!"\%
{ a]VGUW-
System.err.println(sMsg); ]RFdLV?
} amB@N6*
} <uF [,
9[|4[3K
hr U :Wr
/* j.QHkI1.
**TestMethod.java GzdgL"M[
*/ &P n]
package NetFox; c#q"\"
A'"-m)1P
!z=pP$81
public class TestMethod { M g!ra"
1| xN%27>
'H=weH
public TestMethod() 3B,QJ&
{ ///xx/weblogic60b2_win.exe *:arva5
try{ lvufkVG|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); qB JRS'6'9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); v>WB FvyD
SiteFileFetch fileFetch = new SiteFileFetch(bean); [(cL/_
fileFetch.start(); zeTszT)
} z`'P>.x
catch(Exception e){e.printStackTrace ();} ^"tqdeCb=
Y(GW0\<
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} DM2Q1Dh3
qWB%),`j>
#,P(isEZ"
public static void main(String[] args) xzK>Xi?
{ %vc'{`P
new TestMethod(); #'NY}6cb$
} sfC@*Y2XT
} =8S}Iat
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