http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); Q)[C?obd v
} > "=>3
for(int i=0;i<nEndPos.length-1;i++) J6aef^>
{ & 9 ?\b7
nEndPos = nStartPos[i+1]; w)Qp?k d
} 2('HvH]k
nEndPos[nEndPos.length-1] = nFileLength; Hg$lXtn]
} w G<yBI0
} 46&/gehr
/d<P-!fK
~La>?:g <+
//启动子线程 EJNU761
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fsWTF<Y
for(int i=0;i<nStartPos.length;i++) 'CkIz"Wd
{ 'y3!fN=h
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Fun^B;GA:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), vOpKNp
nStartPos,nEndPos,i); 7s{GbU\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <<R*2b
fileSplitterFetch.start(); kq,ucU%>p
} e&aWq@D
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r? E)obE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Da&]y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8q}q{8
nEndPos = " + nFileLength); V /V9B2.$
// fileSplitterFetch[nPos.length-1].start(); UQ@L V~6{R
?oHpFlj
u($!z^h
//等待子线程结束 R',rsGd`6j
//int count = 0; ^qD$z=z-
//是否结束while循环 |2n4QBH!
boolean breakWhile = false; @7j AL-
K}MK<2vU
6MMOf\
while(!bStop) cP_.&!T
{ JHTSUq
write_nPos(); o="M
Utility.sleep(500); zv,jM0-
breakWhile = true; l3I:Q^x@
u frL<]A
pohp&Tcm
for(int i=0;i<nStartPos.length;i++) }oGA-Qc}B
{ ~gZLY ls
if(!fileSplitterFetch.bDownOver) Q:k}Jl
{ j yUCH*@
breakWhile = false; DwE[D]7o
break; 8i#2d1O
} !58@pLJw
} !\.pq 2
if(breakWhile) ^N{h3b8
break; *]/zc1Q4M
&H/'rd0M
D (?DW}Rqs
//count++; iN8zo:&Z
//if(count>4) M{T-iW"
// siteStop(); Lhb35;\
} *kDCliL
IE/^\ M
ieCEo|b
System.err.println("文件下载结束！"); )g#T9tx2D
} 0Y{yKL
catch(Exception e){e.printStackTrace ();} G.abql
} ]tRu2Ygf
dufu|BL|}
Ata:^qI
//获得文件长度 :hk5 .[
public long getFileSize() %oa-WmWm
{ 3>`mI8$t
int nFileLength = -1; }"%?et(
try{ EGU 0)<
URL url = new URL(siteInfoBean.getSSiteURL()); SdxDa
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9BBmw(M}
httpConnection.setRequestProperty("User-Agent","NetFox"); kr:^tbJ
a:IC)]j$_
EF}\brD1
int responseCode=httpConnection.getResponseCode(); nIy}#MUd|q
if(responseCode>=400) Y}|X|!0x
{ vJc-6EO
processErrorCode(responseCode); T9_RBy;%
return -2; //-2 represent access is error >T3-
} V>-e y9Q\
q"sed]
]e>w}L(gV
String sHeader; !_D0vI;
9YQb&
^{;oM^Q'
for(int i=1;;i++) Z<y I\1
{ [KaAXv .X
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ipgC RHE
//Utility.log(in.readLine()); j8{i#;s!"
sHeader=httpConnection.getHeaderFieldKey(i); rt~d6|6
if(sHeader!=null) Tc &z:
{ 6J6BF%
if(sHeader.equals("Content-Length")) .A{tQ1&_
{ QIvVcfM^
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ^"1n4im
break; ~{B7 k:
} ju8q?Nyhs
} bj0G5dc=
else A_ N;
break; 0c'<3@39k|
} KNpl:g3{<Q
} yyRiP|hJ
catch(IOException e){e.printStackTrace ();} Ln<`E|[29
catch(Exception e){e.printStackTrace ();} =eXU@B
A) %/[GD2
)j(7]uX`
Utility.log(nFileLength); L Mbn
[{<`o5qR
[-k
return nFileLength; x_6[P2"PP
} ?o4C;
2%@4]
Tx=-Bb~;
//保存下载信息（文件指针位置） wb5baY9
private void write_nPos() *,8^@(th
{ OSWYGnZg
try{ zrL$]Oy}x
output = new DataOutputStream(new FileOutputStream(tmpFile)); w/S%YW3*
output.writeInt(nStartPos.length); [OV"}<V
for(int i=0;i<nStartPos.length;i++) mPN@{.(j
{ aa?b`[Xa
// output.writeLong(nPos); H*&f:mfq
output.writeLong(fileSplitterFetch.nStartPos); }{qZ[/JwqN
output.writeLong(fileSplitterFetch.nEndPos); k,E{C{^M
} )=Z>#iH1
output.close(); @6F#rz
} N~d?WD\^
catch(IOException e){e.printStackTrace ();} ceh j;
catch(Exception e){e.printStackTrace ();} "9P>a=Y
} \y)rt )
{ MSkHf=
|\<`Ib4j
//读取保存的下载信息（文件指针位置） v/0QOp
private void read_nPos() j4qR(p(vC
{ }=UHbU.n~!
try{ E$:*NSXj
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); W*4-.*U8a
int nCount = input.readInt(); ox>^>wR*
nStartPos = new long[nCount]; O=&0H|B
nEndPos = new long[nCount]; m!4ndO;0vh
for(int i=0;i<nStartPos.length;i++) Ins`l
{ )}]g] g
nStartPos = input.readLong(); S)k*?dQ##R
nEndPos = input.readLong(); I<4Pur>"
} gsvuE
input.close(); " 4K(jXq|
} goRL1L,5
catch(IOException e){e.printStackTrace ();} f/NH:1)y
catch(Exception e){e.printStackTrace ();} ?(y*nD[a
} |`f$tj
Z!#!Gu*V
1onM j
private void processErrorCode(int nErrorCode) z8~NZ;A
{ \oXpi$
System.err.println("Error Code : " + nErrorCode); +p_CN*10H
} pb?c$n$u*
`PdQX.wN
NP#w+Qw
//停止文件下载 /k6MzFoid
public void siteStop() *{@Nq=fE
{ u\x}8pn
bStop = true; &)Tdc
for(int i=0;i<nStartPos.length;i++) OwUhdiG
fileSplitterFetch.splitterStop(); 5\sd3<:+
+L|?~p`V
/y#f3r+*2
} [f-?ymmT
} mpEK (p
//负责部分文件的抓取 Sh~dwxp*"
**FileSplitterFetch.java }6}l7x
*/ r CHl?J
package NetFox; JEwa &
@=Uh',F
OU(8V^.
import java.io.*; s1$nvTzBr
import java.net.*; u+e{Mim
Uq,^Wy
v ~?qz5:K~
public class FileSplitterFetch extends Thread { >,Ci?[pf
fZzoAzfv2
KKPh~ThC
String sURL; //File URL E`0?
long nStartPos; //File Snippet Start Position C8:f_mJU
long nEndPos; //File Snippet End Position [M}{G5U.
int nThreadID; //Thread's ID '8.r-`l(
boolean bDownOver = false; //Downing is over /?'FE 7Y
boolean bStop = false; //Stop identical #7$ H
FileAccessI fileAccessI = null; //File Access interface mh{d8<Q2
$Sx'sA2
R)(T^V`{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException omu|yCK
{ ufZDF=$7
this.sURL = sURL; =/+-<px
this.nStartPos = nStart; j'<<4.(
this.nEndPos = nEnd; gHEu/8E
nThreadID = id; x0D*U?A
fileAccessI = new FileAccessI(sName,nStartPos);//定位 sPQQ"|wU
} [{,T.;'<j
Apag{Z]^B
\?ZB]*Fu
public void run() sA/D]W.P
{ "]x'PI 4J
while(nStartPos < nEndPos && !bStop) Y%aCMP9j~9
{ PfD.:amN7
~i{(<.he
TG?brgW
try{ e/&{v8Hmb
URL url = new URL(sURL); ]BZA:dd.G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f=Gg9bnm3
httpConnection.setRequestProperty("User-Agent","NetFox"); &|ex`nwc0
String sProperty = "bytes="+nStartPos+"-"; y0.'?6k
httpConnection.setRequestProperty("RANGE",sProperty); z}9(x.I
Utility.log(sProperty); w"|L:8
1..+F0U
a=1@*ID
InputStream input = httpConnection.getInputStream(); 8.=BaNU
//logResponseHead(httpConnection); =.U[$~3q%
q=m'^ ,gPS
oj<gD
byte[] b = new byte[1024]; $am$EU?s
int nRead; t!X.|`h
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :zbQD8jv
{ Hqx-~hQO
nStartPos += fileAccessI.write(b,0,nRead); KYhwOGN
//if(nThreadID == 1) b<ZIWfs
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9(7-{,c
} uEP*iPLD@
"ycJ:Xv49
^j7Vt2-
Utility.log("Thread " + nThreadID + " is over!"); 6=/F$|
bDownOver = true; mb3"U"ohs
//nPos = fileAccessI.write (b,0,nRead); |4zIfAO
} cn3\kT*
catch(Exception e){e.printStackTrace ();} su(1<S}
} rJTa
} F6|]4H.3Q
RVmh6m
EU;9*W<
//打印回应的头信息 >dD@j:Qc
public void logResponseHead(HttpURLConnection con) 1{.|+S Z!
{ 70nqD>M4
for(int i=1;;i++) GPudaF{
{ ]Sz:|%JP1
String header=con.getHeaderFieldKey(i); e}7lBLK]*
if(header!=null) n\'4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); yYYSeH
Utility.log(header+" : "+con.getHeaderField(header)); EGS)b
else (gU!=F?#m
break; )m)-o4c
} xml7Uarc
} pRpBhm;iJ
m,w A:o$'
hEH?[>9
public void splitterStop() rfg'G&A(
{ `25yE/
bStop = true; ]|ag
} 4f@rv^f(X
7U"g3a)=
itP,\k7>d
} *#|&JIEsi
783,s_
>\#*P'y`d
/* Eyqa?$R
**FileAccess.java C2I_%nU Z1
*//文件访问(定位，写) 'sKk"bi;0
package NetFox; $( kF#
import java.io.*; "|q&ea rc
k%#EEMh
hWLA<wdb
public class FileAccessI implements Serializable{ lgy<?LI\
!i}w~U<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8/cX]J
RandomAccessFile oSavedFile; 5Ln,{vsv
long nPos; AeM^73t
BwpqNQN
MKk\ u9
public FileAccessI() throws IOException B dfwa
{ RSRS wkC
this("",0); {\1?ZrCI&
} \?-<4Bc@
Hzz %3}E
yx[/|nZDC4
public FileAccessI(String sName,long nPos) throws IOException 7xlkZF
{ Mb}QD~=M
oSavedFile = new RandomAccessFile(sName,"rw"); 8kIksy
this.nPos = nPos; 1R%.p7@5QU
oSavedFile.seek(nPos); Pmx-8w
} )2o?#8J
gz9j&W.
JPHL#sKyz
public synchronized int write(byte[] b,int nStart,int nLen) z&\a:fJ&
{ iWkWR"ysy
int n = -1; |YWD8 +
try{ adcE'fA<_
oSavedFile.write(b,nStart,nLen); EME|k{W
n = nLen; ]s'as9s9
} Q3~H{)[Kq
catch(IOException e) a58H9w"u)
{ =y*IfG9b
e.printStackTrace (); t{9GVLZ
} \V63qg[
g:@#@1rB6
oZgjQM$YP
return n; <xm7qmqI
} %wy.TN
>]TWXmx/w
9.-S(ZO
} C{rcs'
~ .g@hS8>
zC!t;*8a
/* `U_)98
**SiteInfoBean.java 6d}lw6L
*/ /{_:{G!Q0
package NetFox; 9TC,!0U{_.
q3!bky\
@S;'@VC
public class SiteInfoBean { /,yd+wcW#
!e<^? r4
kDioD
private String sSiteURL; //Site's URL + &Eqk
private String sFilePath; //Saved File's Path YD6'#(
private String sFileName; //Saved File's Name (w3YvG.
private int nSplitter; //Count of Splited Downloading File X+9>A.92
ZLejcYS
ouQ T
public SiteInfoBean() k4;7<j$ir
{//nSplitter的缺省值为5 4+8@`f>s
//default value of nSplitter is 5 g3y~bf
this("","","",5); "KpGlY?^
} H7n>Vx:L-
0{D'n@veP
va@Lz&sAE%
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) k4J+J.|
{ !F$6-0%
sSiteURL= sURL; gwMNYMI
sFilePath = sPath; _G@GpkSe>
sFileName = sName; ZY+qA
this.nSplitter = nSpiltter; ;A*]l'[-
oMa6(3T?E
I\ob7X'Xu!
} 4D4j7
Y:[u1~a
u*`GiZAO
public String getSSiteURL() 8lrpve
{ #X1ND
return sSiteURL; <bWG!ZG
} TvbE2Q;/UL
WOap+
TC*g|d @b
public void setSSiteURL(String value) #*Ctwl,T
{ 3s#N2X;Bc
sSiteURL = value; y<Ot)fa$
} F]&*ow
+mn[5Y}:
4tBYR9|
public String getSFilePath() H.MI5O(Q
{ O\r0bUPE
return sFilePath; ~9@UjQ^)F
} kxv1Hn"`{E
.ioEIsg
hwv/AnX~O
public void setSFilePath(String value) \4fQMG
{ c^W)07-X5y
sFilePath = value; a:w#s}bL
} &^jXEz;
` Sz}`+E
G 3ptx! D
public String getSFileName() NgPk&niM
{ bk[!8-b/a
return sFileName; R6->t #n,
} zO6oT1I
\9T7A&
-iZ`Y?
public void setSFileName(String value) 3Y$GsN4ln
{ Q$"D]!G
sFileName = value; FYQS)s
} ;2QP7PrSY
|A(Iti{v
tCt#%7J;a
public int getNSplitter() +ZP7{%
{ p`qgrI`
return nSplitter; ?:0Jav
} Mo|2}nf
(E1~H0^
>m\(6x8RE
public void setNSplitter(int nCount) m8[j #=h
{ v]UwJz3<
nSplitter = nCount; (ToUgVW1N
} xAm6BB c
} a%0EiU
QMm%@zH
[$UI8tV
/* t]G:L}AOl
**Utility.java X:{!n({r=
*/ @H8EWTZ
package NetFox; -KbYOb
!&E-}}<
vl)l'
public class Utility { Ow,b^|
8z\xrY
]Hv[IodJ
public Utility() #/37V2E
{ Fsg*FH7J
F!K>Kz
Tid aa
} \i&<s;
COlaD"Y
//线程睡眠 Z;"vW!%d
public static void sleep(int nSecond) f|(M.U-
{ 6Kz,{F@
try{ 9>#6*/Oa7
Thread.sleep(nSecond); K*dCc}:`
} @C aG9]
catch(Exception e) A3*!"3nU
{ %;!.n{X
e.printStackTrace (); qqU 64E
} hi[pVk~B)
} 5!9zI+S|=`
Flb&B1
//日志 xgtR6E^k
public static void log(String sMsg) yB6?`3A:
{ -UT}/:a
System.err.println(sMsg); HxI" 8A
} c:.eGH_f
&%Tj/Qx
|4`{]2C
public static void log(int sMsg) 93hxSRw
{ ,2ar7 5Va
System.err.println(sMsg); 1h5 Akq
} C7AUsYM
} }(u ol
e96k{C`j0
&cTU sK
/* FVBYo%Ap
**TestMethod.java }ad|g6i`
*/ ovV'VcUs
package NetFox; RG`1en
i!Ga5v8n:
<a+Z;>
public class TestMethod { QmIBaMI#
Z?z.?ar
? =+WRjF
public TestMethod() 9cm#56
{ ///xx/weblogic60b2_win.exe {(}By/_
try{ Z/J y'$x
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9_s`{(0?
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Aiea\jBv
SiteFileFetch fileFetch = new SiteFileFetch(bean); t#"Grk8Mz&
fileFetch.start(); {l>hMxij
} +nGAz{&@r%
catch(Exception e){e.printStackTrace ();} E4xa[iZ
w%sT{(Vd`C
LreP4dRe
} Y nZiTe@
/u+e0BHo
n'w.; q
public static void main(String[] args) xN%K^Tree
{ ;bhT@aB1
new TestMethod(); uW3!Yg@
} WjqO@]P6
} v*yuE5{
点击下载更多相关资料