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)); 6k])KlJ2;
} 4ax|Vb)D
for(int i=0;i<nEndPos.length-1;i++) W^g[L:s
{ w,.qCpT$_
nEndPos = nStartPos[i+1]; !UV5zmS
} N:+ taz-
nEndPos[nEndPos.length-1] = nFileLength; fW0$s`
} /k:$l9C[
} 83]PA<R
00vBpsZj2;
b_$1f>
//启动子线程 xc'vS>&
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1H4fJ3-
for(int i=0;i<nStartPos.length;i++) y@vj;3:
{ Q]JX`HgPaU
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &hZwZgV+3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?Z %:
nStartPos,nEndPos,i); p5]_}I`+2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BQgoVnQo_c
fileSplitterFetch.start(); {_ V0
} "/x_>ui1F
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), whc[@Tyx
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ~o15#Pfn/
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", b#Kq[}
nEndPos = " + nFileLength); (wt+`_6
// fileSplitterFetch[nPos.length-1].start(); k{Lv37H
/Ic[N&
OHp5z? z
//等待子线程结束 p6 xPheD
//int count = 0; v"1Po_`
//是否结束while循环 =fG:A(v%}
boolean breakWhile = false; zQuM !.
2:v<qX
@Jv# fr
while(!bStop) z%"Ai)W/{
{ \SYvD y]
write_nPos(); |'hLa
Utility.sleep(500); "G?9b
breakWhile = true; SN]LeXesS
,jh~;, w2
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for(int i=0;i<nStartPos.length;i++) \aSz2lxEHn
{ ZCiY,;c
if(!fileSplitterFetch.bDownOver) o42`z>~
{ Pern*x9$
breakWhile = false; {7#03k
break; x*8O*!ZZ
} h W.2p+
} C|e+0aW
if(breakWhile) $-G`&oT
break; Lar r}o=
Lx+`<<_dJ
12gw#J/)9h
//count++; fD6GQ*
//if(count>4) emWGIo
// siteStop(); .LE+/n
} .H;B=nd*
c4]u&tvjJ
;L6Xs_L~
System.err.println("文件下载结束！"); L$JI43HZ
} wJIB$3OT
catch(Exception e){e.printStackTrace ();} Ph)|j&]
} oX|?:MS:
QrS$P09=\
!t-K<'
//获得文件长度 9O >z4o
public long getFileSize() 9)ea.Gu
{ ~mA7pOHj
int nFileLength = -1; L+R>%d s
try{ vfbe$4mH
URL url = new URL(siteInfoBean.getSSiteURL()); 7*'@qjTos
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); rWr/p^~
httpConnection.setRequestProperty("User-Agent","NetFox"); yh!B!v'
8eX8IR!K9
05)|"EX)
int responseCode=httpConnection.getResponseCode(); l{EU_|q
if(responseCode>=400) Yo'K pdn
{ (T;9us0
processErrorCode(responseCode); T&/_e
return -2; //-2 represent access is error nLd~2qBuv
} &z ksRX
NV~vuC
Zz")`hUG
String sHeader; JD&U}dJ
#: hVF/
)0|):g
for(int i=1;;i++) /co%:}ln
{ j`9Nwa
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 3H'*?|Y(#
//Utility.log(in.readLine()); FfXZ|o$;
sHeader=httpConnection.getHeaderFieldKey(i); K -E`y
if(sHeader!=null) DB8s
{ 1f;or_f#k?
if(sHeader.equals("Content-Length")) 41'EA\V
{ ,9vJtP+T+!
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); kH2oK:lN
break; m<FK;
} C1ZyB"{
} o*;2mFP
else )Pa*+ew7
break; +2yF|/WW#
} u:5IjOb2^
} $3:X+X
catch(IOException e){e.printStackTrace ();} )[ b#g(Y(
catch(Exception e){e.printStackTrace ();} @LC~*_y
UT;4U;a,m
}} #be
Utility.log(nFileLength); dJE`9$jN
X7&U3v
@ RX`>r{_
return nFileLength; |D(&w+(
} {Y"8~
aH^{Vv$]M@
tQf!|]#J
//保存下载信息（文件指针位置） ^Fvr f`A'
private void write_nPos() T^NJ4L4#
{ o'^phlX
try{ Z"N(=B
output = new DataOutputStream(new FileOutputStream(tmpFile)); x_|>n<Z
output.writeInt(nStartPos.length); qOgtGN}k
for(int i=0;i<nStartPos.length;i++) bQV("~#
{ oVEAlBm^v
// output.writeLong(nPos); <4$YO-:E
output.writeLong(fileSplitterFetch.nStartPos); X#7}c5^Y
output.writeLong(fileSplitterFetch.nEndPos); v,*Q]r0m
} D+hB[*7Fs
output.close(); #{~7G%GPY5
} |Cq8%
catch(IOException e){e.printStackTrace ();} DUo0w f#D^
catch(Exception e){e.printStackTrace ();} N*':U^/t4J
} wO!% q[
3B -NYJa
xfes_v""
//读取保存的下载信息（文件指针位置） ?"u'#f_
private void read_nPos() )O -cw7 >
{ 26}u4W$
try{ FdM<;}6T
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g~|y$T
int nCount = input.readInt(); R9q0,yQW
nStartPos = new long[nCount]; 59~FpjJ
nEndPos = new long[nCount]; r hZQQOQ
for(int i=0;i<nStartPos.length;i++) c-`37. J
{ r8F{A6iN
nStartPos = input.readLong(); Mb~~A5
nEndPos = input.readLong(); b_ZNI0Hp@
} pd7O`.3
input.close(); t#{x?cF
} e@yx}:]h
catch(IOException e){e.printStackTrace ();} )5'rw<:="
catch(Exception e){e.printStackTrace ();} H8sK}1.
} ,b4~!V
3Cd<p[%3#,
[xWEf#', !
private void processErrorCode(int nErrorCode) Tfr`?:yF
{ \d ui`F"Cc
System.err.println("Error Code : " + nErrorCode); {sl~2#,}b1
} avVmY|I
YV4 :8At1
EZ*t$3.T
//停止文件下载 _Ws#UL+Nq
public void siteStop() 4*H(sq
{ tr5'dX4]
bStop = true; +*: }p
for(int i=0;i<nStartPos.length;i++) S;>4i!Mb ^
fileSplitterFetch.splitterStop(); C)U #T)
),MU+*`
9n-T5WP
} e"lD`*U8R
} (;C$gnr.C
//负责部分文件的抓取 2c"/QT
**FileSplitterFetch.java '1Y<RD>x
*/ T<XfZZ)l<`
package NetFox; 8F\~Wz7K
(y 3~[
ZRX^^yN
import java.io.*; ^uM_b
import java.net.*; BB0g}6M
k"5`:qL
\ hrBq^I
public class FileSplitterFetch extends Thread { gO9'q='5l
u/;_?zI
2 aew6~
String sURL; //File URL `!<x"xKu
long nStartPos; //File Snippet Start Position \)p4okpR
long nEndPos; //File Snippet End Position ^4RO
int nThreadID; //Thread's ID ~d&'Lp[3
boolean bDownOver = false; //Downing is over Tm%WWbc
boolean bStop = false; //Stop identical aD?# ,
FileAccessI fileAccessI = null; //File Access interface Z(l9>A7!
%Fs*#S
5Ws5X_?d
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException AL(n*,
{ i[o&z$JO
this.sURL = sURL; -<]\l3E&J
this.nStartPos = nStart; Av@&hD\
this.nEndPos = nEnd; gHp'3SnS
nThreadID = id; >c}:
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0&.LBv8
} zoR,RBU6
CQj/e+eE4
x`Vy<h 33
public void run() 4u@yJ?U
{ <zfO1~^
while(nStartPos < nEndPos && !bStop) =VCi8jDkP
{ /]pX8 d
_RN/7\
W]} #\\$z
try{ u):X>??
URL url = new URL(sURL); jG =(w4+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A J<iM)l|
httpConnection.setRequestProperty("User-Agent","NetFox"); X77A; US
String sProperty = "bytes="+nStartPos+"-"; @gs26jX~2}
httpConnection.setRequestProperty("RANGE",sProperty); 37J\i ]
Utility.log(sProperty); <GSQ2bX[
ww-XMz h
|*lH9lWJ
InputStream input = httpConnection.getInputStream(); A$%@fO.b
//logResponseHead(httpConnection); Q~x*bMb.
j@%K*Gb`
>|v=Ba6R0
byte[] b = new byte[1024]; p Z0=
int nRead; eL>K2Jxq
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Z'voCWCd
{ bMSD/L
nStartPos += fileAccessI.write(b,0,nRead); 8W(<q|t
//if(nThreadID == 1) Ti0 (VdY
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ac2}3$u
} N;e;4,_ n
OJnPP>
-OHvK0~
Utility.log("Thread " + nThreadID + " is over!"); pI'8>_o
bDownOver = true; _K 4eD.
//nPos = fileAccessI.write (b,0,nRead); $ijx#a&O
} 8yY"x ['
catch(Exception e){e.printStackTrace ();} 71K\.[ =-
} Na~g*)uT$
} +J\L4ri k
p*A^0DN'Fn
.q AQPL
//打印回应的头信息 ~,(0h:8
public void logResponseHead(HttpURLConnection con) 113Z@F
{ SIKk|I)
for(int i=1;;i++) d)`nxnbMeM
{ \9dz&H
String header=con.getHeaderFieldKey(i); trID#DT~
if(header!=null) n,CD4Nv
//responseHeaders.put(header,httpConnection.getHeaderField(header)); l=Lmr
Utility.log(header+" : "+con.getHeaderField(header)); ^G]KE8
else 4v rm&k
break; :6\-9m8JM
} uYG #c(lc
} HV]~=Bw2I
+ TPbIRA
>WGX|"!"
public void splitterStop() m]+X}|
{ 9'L1KQ
bStop = true; ucIVVT(u
} T{5M1r
|U;w!0
$bF`PGR_
} $ioaunQKP
TMnT#ypf<5
umq$4}T'$
/* z{ Zimr
**FileAccess.java Qs#9X=6e@
*//文件访问(定位，写) ?M*C*/R
package NetFox; Hl4vLx@
import java.io.*; &F@tmM~
'=@-aVp
"B_5Y&pM`
public class FileAccessI implements Serializable{ Zq2H9^![y~
g7E`;&f
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ONg<
RandomAccessFile oSavedFile; ~m,mvRS
long nPos; \?5[RR
JCCx 5
:O>Nd\UtO
public FileAccessI() throws IOException I(iGs I
{ i]hR7g<
this("",0); =CD:.FG.
} A;/Xt
fzPgX
K284R=j -&
public FileAccessI(String sName,long nPos) throws IOException }RC.Q`b
{ 4nVO.Ud0$X
oSavedFile = new RandomAccessFile(sName,"rw"); (o6A?37i
this.nPos = nPos; K4K3<Pg
oSavedFile.seek(nPos); -7C=- \]
} (AyRs7Dkn
hs -}:^S`
#U6/@l)
public synchronized int write(byte[] b,int nStart,int nLen) /_ hfjCE
{ g:@Cg.q8
int n = -1; |zr)hC
try{ A ydy=sj
oSavedFile.write(b,nStart,nLen); uMq\];7I
n = nLen; 6 ^6uK
} {kY`X[fvZ
catch(IOException e) z~A(IQO
{ 1*eWvYo1
e.printStackTrace (); A-@-?AR
} >E2WZHzd2
Hsux>+Q
%Pt[3>
return n; unbcz{&Hb[
} K7d1(.
HeAc(_=C
`siy!R
} "~i#9L/H
:#"OCXr
U8.0L
/* $D2Ain1
**SiteInfoBean.java *(XgUJq+
*/ c+\Gd}IJq
package NetFox; QKL]O*
QtO[g
=-a?oH-
public class SiteInfoBean { y+~Aw"J}
.,iw2:
l*V72!Mv
private String sSiteURL; //Site's URL (t"YoWA#m
private String sFilePath; //Saved File's Path PHB\)/
private String sFileName; //Saved File's Name *< SU_dAh
private int nSplitter; //Count of Splited Downloading File N]<~NG:6b
F0o18k_"
oeU+?-y/b
public SiteInfoBean() `b,g2XA
{//nSplitter的缺省值为5 G@l|u
//default value of nSplitter is 5 vr]dRStr
this("","","",5); 5"Xo R)
} 6b1 Uj<
mhHm#
::Ve,-0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) n$\6}\k
{ =}1~~
sSiteURL= sURL; K`AW?p^$Y
sFilePath = sPath; {3yws4
sFileName = sName; lf7H8k,-
this.nSplitter = nSpiltter; 7C6BZ$(
}e;p8)]Wl
nh_xbo5L[
} 9ixnf=$Jp
G#=b6DB
S3[oA&
public String getSSiteURL() L:];[xa%
{ hF?\K^tF
return sSiteURL; e1Z;\U$&.
} #xE>]U
s9)8{z
J1wGK|F~
public void setSSiteURL(String value) %>QSeX
{ e[Ul"pMvS`
sSiteURL = value; l=.InSuLT
} DyV[+P
(j\UoKLRt
bgx5{!A
public String getSFilePath() _M[[o5{
{ (>/Dw|,m
return sFilePath; r;s3(@[,@
} )Z`viT
.~/;v~bL
}N=zn7W
public void setSFilePath(String value) I5AjEp
{ jq]\oY8y
sFilePath = value; ]{l O
} 4?6'~G$k
\}_7^)S;
L``mF(R^
public String getSFileName() =dJEcC_J
{ :y)&kJpleP
return sFileName; tLGwF3e$A
} 75cr!+
vmQ DcCw
&qj&WfrB,
public void setSFileName(String value) E!]rh,mYK
{ :j!_XMyT:
sFileName = value; wz2)seZY
} UM;bVf?
B=qRZA!DQ?
AFnlt
public int getNSplitter() [}B{e=`!
{ l=G#gKE
return nSplitter; <Ucfd G&Lp
} (inwKRH
v6(l#,
gl4 f9Ff
public void setNSplitter(int nCount) )e$-B]>7z
{ BB}iBf I'
nSplitter = nCount; s#CEhb
} !haXO
} 5|H(N}S_
t@mw f3,
5+PBS)pJ]%
/* RAJ|#I1
**Utility.java Kwmo)|7uPU
*/ ;bu;t#
package NetFox; '48|f`8$
eh# (}v
-cC(d$y
public class Utility { olW`.3f
_p^ "!
w\[*_wQp
public Utility() sJ*U Fm{
{ 0hr)tYW,G
LGue=Hkp
g{.@|;d<p
} <\Dl#DH
)=y6s^}
//线程睡眠 |Szr=[
public static void sleep(int nSecond) ~.=HN}E
{ rY+1s^F
try{ |0Ug~jKU
Thread.sleep(nSecond); 7o%|R2mL}
} {@`Uf;hPAX
catch(Exception e) =*G'.D /*
{ <{~UKi
e.printStackTrace (); ;&:Et
} Aba%Gh
} \{^yB4F_Z
?DTP-#5Ba
//日志 h1d0{
public static void log(String sMsg) B$eF@v"
{ S~`AnX3!
System.err.println(sMsg); Or~6t}f
} :l[Q
nqW:P$
im%3*bv-
public static void log(int sMsg) 2n,73$s
{ 833t0Ml1A/
System.err.println(sMsg); "+C\f)
} y^fU_L?p
} sX?7`n1U
UjK&`a;V
SQ.Wj?W)
/* Dy'l]vN$
**TestMethod.java qt;Tfuo
*/ V'4}9J
package NetFox; 0X6o
qOanu
pNsLoNZ3w
public class TestMethod { (M?Q9\X
_ q1|\E%`h
+F6_P
public TestMethod() =1?yS3
{ ///xx/weblogic60b2_win.exe '.v^seU
try{ *g}&&$b0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); XsMphZnK
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Lu5.$b
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1F8EL)9
fileFetch.start(); -w0>4JDs
} y`dzo`f
catch(Exception e){e.printStackTrace ();} (NlEb'~+
YCdxU1V
Z*B(L@H
} (KU@hp-\
0u9h2/ma
BGjTa.&
public static void main(String[] args) |ZzBCL8q
{ nAj2k
new TestMethod(); tS@/Bq('B
} Bbp9Q,4
} bS"M*
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