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)); qzG'Gz{{qu
} :')<|(Zy
for(int i=0;i<nEndPos.length-1;i++) D?E5p.!A
{ Wl,yznT
nEndPos = nStartPos[i+1]; S}|ea2
} a( qw
nEndPos[nEndPos.length-1] = nFileLength; 3)7'dM
} 1n,JynJ
} 6-^+btl)#
Oll\T GXP!
VOiphw`
//启动子线程 /q^( uWu
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;xRyONt
for(int i=0;i<nStartPos.length;i++) 9DT}sCLz:B
{ d EXw=u
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), oDRNM^gz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), z C``G<TB
nStartPos,nEndPos,i); ?LW1D+
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1k7E[G~G|
fileSplitterFetch.start(); X$xqu\t7
} "47nc1T+n
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &A`QPk8n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); UOwj"#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Y8N&[L[z&
nEndPos = " + nFileLength); /RMep8&
// fileSplitterFetch[nPos.length-1].start(); .FC1:y<aO
]l\J"*"aB
4]g^aaQFd>
//等待子线程结束 ;m\(fW*ii
//int count = 0; t EN%mK
//是否结束while循环 Gh< r_O~L3
boolean breakWhile = false; W[vak F
LPXwfEHOm
f&,.h"bS
while(!bStop) [m4<j
{ f{vnZ|WD
write_nPos(); 4f>Vg$4
Utility.sleep(500); qzH97<M}T
breakWhile = true; > vahj,CZZ
'E@D
AvwX 2?tc
for(int i=0;i<nStartPos.length;i++) eC3ZK"oJ
{ }b{N[
if(!fileSplitterFetch.bDownOver) 1\3n
{ 7+z%O3k'I
breakWhile = false; )i?wBxq'MA
break; TcqqAc
} ?iq:Gf
} Coyop#q#"{
if(breakWhile) ZA# jw 8F
break; 4[(P>`Unx
18`?t_8g
E0*81PS
//count++; mjw:Z,
//if(count>4) ?>w%Lg{L}
// siteStop(); >yaz
} sQ_{zOUPh
zi5;>Iv0}
mO\6B7V!
System.err.println("文件下载结束！"); avT>0b:
} U_!6pqFc
catch(Exception e){e.printStackTrace ();} {:? -)Xq
} N#UyAm<9
S |B7HS5
ul:jn]S*
//获得文件长度 NQOdgp
public long getFileSize() !]"T`^5,Y
{ cLXMq"?C
int nFileLength = -1; uYs+xX_
try{ *f,EDSN1@d
URL url = new URL(siteInfoBean.getSSiteURL()); +DU}f;O8v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8J@REP4
httpConnection.setRequestProperty("User-Agent","NetFox"); EJRwyF5LK
F&uU ,);
Va{`es)hky
int responseCode=httpConnection.getResponseCode(); .<tb*6rX>
if(responseCode>=400) PB`94W
{ 6.k2,C4dT<
processErrorCode(responseCode); f-3lJ?6
return -2; //-2 represent access is error }?H|9OS
} d-c+KV
1c\$ziB
DSQ2z3s2
String sHeader; ,Z3.Le"
Y(-+>>j_
>`t |a
for(int i=1;;i++) [aIQ/&Y
{ ;ASlsUE\)
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); uRp-yu[nt%
//Utility.log(in.readLine()); **oN/5
sHeader=httpConnection.getHeaderFieldKey(i); "EA%!P:d,
if(sHeader!=null) d^,u"Z9P
{ UD.$C
if(sHeader.equals("Content-Length")) b2ZKhS8
{ zHyM@*Gf(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [t>}M6?R:
break; 4Sw)IU~K(
} .)Du ;
} &'i>5Y
else k3u3X~u
break; /9i2@#J}W1
} Id9hC<8$dq
} teET nz_L
catch(IOException e){e.printStackTrace ();} N 0`)WLW
catch(Exception e){e.printStackTrace ();} 7=}`"7i~
Y68oBUd_E
g"F vD_
Utility.log(nFileLength); [ibnI2I]`
Q xKC5`1
-cOLgrmp
return nFileLength; A5z5e# ,u
} {&m^*YN/
3Ju<jXoo!
>+&524xc
//保存下载信息（文件指针位置） eAPGy-
private void write_nPos() xMU4Av[{
{ =r#of|`Q
try{ \y{C>!WX4
output = new DataOutputStream(new FileOutputStream(tmpFile)); s_u@8e 6_
output.writeInt(nStartPos.length); va| 1N/&
for(int i=0;i<nStartPos.length;i++) 4s%vx]E
{ r 5:DIA!
// output.writeLong(nPos); /wKL"M-%
output.writeLong(fileSplitterFetch.nStartPos); \&"gCv#
output.writeLong(fileSplitterFetch.nEndPos); U+URj <)
} fgq#Oi}
output.close(); 6>X7JMRY
} w8c71C
catch(IOException e){e.printStackTrace ();} %r?Y!=0
catch(Exception e){e.printStackTrace ();} jq%Qc9y
} #T&''a
/0@'8f\I
0]fzjiaGt
//读取保存的下载信息（文件指针位置） yd'>Mw
private void read_nPos() r 1nl!
{ ;3 O0O
try{ 1o V\QK&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g>cp;co9g
int nCount = input.readInt(); =:uK$>[
nStartPos = new long[nCount]; X=8y$Yy
nEndPos = new long[nCount]; n~@;[=o?5
for(int i=0;i<nStartPos.length;i++) 5PqL#Eu`!
{ VMZ\9IwI
nStartPos = input.readLong(); I& DEF*
nEndPos = input.readLong(); "sdzm%
} Ho2#'lSKM
input.close(); 2h%/exeS;
} 1pg&?L.MA
catch(IOException e){e.printStackTrace ();} pxDkf|*
catch(Exception e){e.printStackTrace ();} Et}S*!IS
} ">@]{e*
i]Njn k
IxkL]
private void processErrorCode(int nErrorCode) uD4on}
{ (p>?0h9[
System.err.println("Error Code : " + nErrorCode); TgoaEufS<
} B<%cqz@
0Q`Dp;a5&
*c3(,Bmw
//停止文件下载 5_!s\5
public void siteStop() *j6KQZ"
{ clV3x`z
bStop = true; db -h=L|
for(int i=0;i<nStartPos.length;i++) W US[hx,
fileSplitterFetch.splitterStop(); H|JPqBNRh
TF R8
98'/yZ
} g0O~5.f
} B]iPixA6
//负责部分文件的抓取 piULIZ0
**FileSplitterFetch.java 0n<>X&X
*/ E^qJ5pr_P
package NetFox; _3~/Z{z8
W|'7)ph
Ve)P/Zz}^
import java.io.*; GJS3O;2*
import java.net.*; ;UUpkOQO(
3Xcjr2]~
:{BD/6
public class FileSplitterFetch extends Thread { uGt}Hn
Vq-W|<7C=
<hkSbJF
String sURL; //File URL ]ie38tX$
long nStartPos; //File Snippet Start Position B>C+qj@
long nEndPos; //File Snippet End Position =S+*=jA
int nThreadID; //Thread's ID ,Pi!%an w
boolean bDownOver = false; //Downing is over M~+}ss
boolean bStop = false; //Stop identical xP/?E
FileAccessI fileAccessI = null; //File Access interface !>RDHu2n
71b0MHNkvv
JPO'1D)
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException aG_@--=
{ M$YU_RPl+
this.sURL = sURL; X\4d|VJ?m
this.nStartPos = nStart; fJ<I|ZZ
this.nEndPos = nEnd; Q3"{v0
nThreadID = id; .bYZkO:oy
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &X3G;x2;
} 03pD<
<fSWX>pR
aW=c.Q.
public void run() `)y<X#[8
{ 00SYNG!
while(nStartPos < nEndPos && !bStop) >^:*x_a9
{ WoV"&9y
Z=ZTSl
A:b(@'h
try{ w :nYsuF
URL url = new URL(sURL); 5}C.^J`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^Y%'"QwJS
httpConnection.setRequestProperty("User-Agent","NetFox"); :Oiz|b(
String sProperty = "bytes="+nStartPos+"-"; P K+rr.k]
httpConnection.setRequestProperty("RANGE",sProperty); .q90+9Ek=
Utility.log(sProperty); ]y0bgKTK
#)r^ZA&E
QHU|aC{r
InputStream input = httpConnection.getInputStream(); |VX )S!
//logResponseHead(httpConnection); &u+l`F^Z
r{>`"
)2sE9G,
byte[] b = new byte[1024]; ,Iv eKk5W
int nRead; ~k"r
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !\< [}2}
{ ^/~ZP?%]
nStartPos += fileAccessI.write(b,0,nRead); dvAG}<
//if(nThreadID == 1) 0 i'bo*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 22OfbwCb
} q\pI&B
6b2Z}B
vmzc0J+3p
Utility.log("Thread " + nThreadID + " is over!"); YjCHKI"e
bDownOver = true; q@Aw]Kh
//nPos = fileAccessI.write (b,0,nRead); o;TS69|D
} VQ"Z3L3-4
catch(Exception e){e.printStackTrace ();} !n7'TM'
} ?kIyo
} "hmLe(jo}
I1pnF61U
,B~5;/|
//打印回应的头信息 57wHo[CJ
public void logResponseHead(HttpURLConnection con) 4aP 96
{ $fCKK&Wy
for(int i=1;;i++) WKAG)4
{ ;FGS(.mjlC
String header=con.getHeaderFieldKey(i); 5rb<u>e{
if(header!=null) O llS
//responseHeaders.put(header,httpConnection.getHeaderField(header)); mv,5Q6!
Utility.log(header+" : "+con.getHeaderField(header)); C547})
else tzShds
break; :5sjF:@
} g#k@R'7E
} \ 5.nr*5
x2,;ar\D
h2-v.Tjf
public void splitterStop() }_Ci3|G>%D
{ 7qSnP30}
bStop = true; ;E_Go&Vd
} 7@&mGUALO
9^u}~e #(
J8-K
} 7W'&v+\
tQ*?L
~GE|,Np
/* Ay7PU
**FileAccess.java AGl#f\_^
*//文件访问(定位，写) /X]gm\x7s
package NetFox; s~QIs
import java.io.*; /Y=_EOS
Q45gC28x
;Fo7 -kK
public class FileAccessI implements Serializable{ Yy~xNj5OS
?W_8X2(`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 xw}rFY$
RandomAccessFile oSavedFile; w\mTug
long nPos; 3@nIoN'z
q*Oj5;
sib/~j
public FileAccessI() throws IOException Ee_?aG e&
{ \2!.
this("",0); k`#E#1niN
} |$;4/cKfy
_&(L{cFx6
T6b~uE
public FileAccessI(String sName,long nPos) throws IOException %K+hG=3O
{ JMk2OK{0
oSavedFile = new RandomAccessFile(sName,"rw"); 8[.&ca/[
this.nPos = nPos; k`o8(zPb
oSavedFile.seek(nPos); :_<&LO]Q
} H | C3{9
3dz{"hV
rb}fP #j
public synchronized int write(byte[] b,int nStart,int nLen) fWC(L s
{ n*ROlCxV
int n = -1; HE{UgU:tY
try{ E,F^!4 rJ$
oSavedFile.write(b,nStart,nLen); Rp;"]Q&b
n = nLen; "@5qjLz]
} (-Q~@Q1
catch(IOException e) ^I|i9MH
{ W[k rq_c-
e.printStackTrace (); f[vm]1#
} Y}xM&%
TQ:h[6v
0i"2s}^+_
return n; {\`y)k 7
} VFM!K$_
|Eh2#K0x4G
} xA@3RT
} =>lX brJ
Lagk
;&gk)w6*
/* +*xc4
**SiteInfoBean.java $a8,C\me?
*/ 3M(*q4A$"
package NetFox; YD@Z}NE v"
FZ RnIg
u Fw1%
public class SiteInfoBean { XZ{rKf2
WO{7/h</
pouXt-%2X
private String sSiteURL; //Site's URL q.<)0nk
private String sFilePath; //Saved File's Path wx`.
private String sFileName; //Saved File's Name '<vb_8.
private int nSplitter; //Count of Splited Downloading File [E%g3>/mt
.I EHjy\+
ji>LBbnHdE
public SiteInfoBean() D"-Wo}"8O'
{//nSplitter的缺省值为5 D5oYcGc
//default value of nSplitter is 5 7QnWw0
this("","","",5); eub}+~_?[
} [mQ1r*[j
aeI0;u
\2=I//YF
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) m&b1H9ymd
{ h_ccE6]t
sSiteURL= sURL; A`JE(cIz3
sFilePath = sPath; 2LR y/ah
sFileName = sName; fVgN8b|&'
this.nSplitter = nSpiltter; I^( pZ9
x:4R?!M.
7]{t^*
} nSh~mP
CbW[_\
[&4+ <Nl'
public String getSSiteURL() '_V9FWDZ
{ lyFlJmi,r
return sSiteURL; ~OsLbz:
} N$#~&
PYWFz
2HSFMgy
public void setSSiteURL(String value) i$p2am8f
{ - AgD
sSiteURL = value; k!z<=WA
} ]Jm\k'u[
u=qaz7E
U?Dr0wD;[
public String getSFilePath() /O.Ql,6[
{ )+'=Zvgej=
return sFilePath; [<{r~YFjWW
} rm ;U'&{
N%>h>HJ
t_xK?``
public void setSFilePath(String value) M*qE)dZjS
{ n*ShYsc
sFilePath = value; 3) d}3w {
} wu eDedz\
n{<}<SVY
5,oLl {S'
public String getSFileName() A?lR[`'u\
{ 3M+rFB}tS
return sFileName; &L5 )v\z
} !wQ?+:6
Al6%RFt
3u[8;1}7Q
public void setSFileName(String value) !QvmzuK
{ TfkGkVR
sFileName = value; P(Rl/eyRM
} J^CAQfcx
eR>8V8@
b/qK/O8J
public int getNSplitter() vdvnwzp!l
{ s@iY'11
return nSplitter; l1lYb;C
} ; U7P{e05
i.7_i78\"
j;E$7QH[
public void setNSplitter(int nCount) h%$^s0w
{ H"^9g3U
nSplitter = nCount; 8<T~AU8'*
} sRZ<c
} F(."nUrf
_0gdt4
dmXfz D
/* wT- <#+L\
**Utility.java =H23eOS_#
*/ J ;z`bk^
package NetFox; l3ogMRq@
Kw;gQk~R!
"0Z/|&
public class Utility { =y@0il+V
8@LWg d
J^7M0A4K
public Utility() K-\wx5#l/
{ 0iZeU:FE
,G46i)E\
aXqig&:
} BF2U$-k4
l4+ `x[^
//线程睡眠 e21J9e6z
public static void sleep(int nSecond) '"\n,3h
{ ^o _J0 ]m
try{ ^78N25RU(
Thread.sleep(nSecond); ;Wy03}K4J
} 7- LjBlH
catch(Exception e) 0\Jeyb2dl
{ "|dhmV[;
e.printStackTrace (); CP;<B1
} WHv6E!^\_
} @{fwM;me]P
W?aP%D"(i
//日志 J|^XD<Y
public static void log(String sMsg) D6?h 6`J
{ E:/!]sm!
System.err.println(sMsg); WvJ:yUb2
} -(WRhBpw
'v0rnIsI?
T}msF
public static void log(int sMsg) N2}Y8aR~
{ ;qUB[Kw
System.err.println(sMsg); ;T0X7MNx
} !LpjTMYs
} F."ZCEb
e4Qjx*[G
PPySOkmS3
/* Dzu//_u
**TestMethod.java BH~zeJ*Pr
*/ r0[<[jEh
package NetFox; 8N"WKBj|_d
\MmOI<Hd-
eHs38X
public class TestMethod { W<#!He
<XDnAv0t
:NWIUN
public TestMethod() /*BU5
{ ///xx/weblogic60b2_win.exe GT]>
try{ oxeu%wj_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Twd*HH
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *My9r.F5o
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4[kyzz x
fileFetch.start(); N;-%:nC
} BxV>s+o&]
catch(Exception e){e.printStackTrace ();} u ynudO
zY*~2|q,s
Cc{{9Ud
} H{N},B
XY? Cl
fB7Jx6
public static void main(String[] args) A_E2v{*n
{ FCwE/ 2,
new TestMethod(); yevJA?C4 v
} iJoYxx
} `<v$+mG
点击下载更多相关资料