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)); `E|>K\
} rLA^ &P:
for(int i=0;i<nEndPos.length-1;i++) Fi# 9L
{ &;U F,
nEndPos = nStartPos[i+1]; Zi<(>@z2
} m,&2s-v
nEndPos[nEndPos.length-1] = nFileLength; |{La@X
} d3NER}f4V
} 4GS:kfti
Aa^w{D
g|M>C:ZT
//启动子线程 tv5N wM
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,r;E[k@
for(int i=0;i<nStartPos.length;i++) Z<'iT%6+r
{ g`4WisL1n
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), MHS|gR.c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ' ?a d
nStartPos,nEndPos,i); !w/]V{9`X
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Yn>FSq^Wp-
fileSplitterFetch.start(); #4V->I
} y:k7eE"
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .2y @@g
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); o;>qsn8
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", AvB21~t&]
nEndPos = " + nFileLength); fONycXM]
// fileSplitterFetch[nPos.length-1].start(); &:~9'-O
MRzY<MD
*r ('A
//等待子线程结束 %&wi@ *#
//int count = 0; SPnW8
//是否结束while循环 {x~r$")c?
boolean breakWhile = false; ]'Gz~Z%>F
L%Ms?`i,
[@NW
while(!bStop) 2#Qw
{ xu@xP5GB^
write_nPos(); QiaBZAol
Utility.sleep(500); =[0|qGzg
breakWhile = true; ()Qq7/
pxCQ=0k
0Y8Cz/$
for(int i=0;i<nStartPos.length;i++) 6 kD.
{ [S0wwWU |0
if(!fileSplitterFetch.bDownOver) 9ZDbZc
{ 9&s>RJ
breakWhile = false; 3S @)Ans
break; )GOio+{H
} o+}G/*O8
} j%gle%_
if(breakWhile) 3~Ll<8fv
break; k|$?b7)"@
|g"K7XfM4
Lc(eY{CY
//count++; CW FE{
//if(count>4) T-x}o
// siteStop(); Q~`{^fo1
} 4r#4h4`y|
y s[z[
NMzq10M=6
System.err.println("文件下载结束！"); 4ZkaH(a1
} z Ece>=C
catch(Exception e){e.printStackTrace ();} {9{PU&?(
} &d]@$4u$;
HrUE?Sq
c7nbHJi
//获得文件长度 =&m;5R
public long getFileSize() D$VRE^k
{ 5>hXqNjP2
int nFileLength = -1; 1/%5pb2\
try{ YUTI)&y
URL url = new URL(siteInfoBean.getSSiteURL()); T/:6Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D5Z)"~'
httpConnection.setRequestProperty("User-Agent","NetFox"); Hxn#vAc
,o}CBB! k
dV /Es
int responseCode=httpConnection.getResponseCode(); 0D0uzUD-
if(responseCode>=400) WT}xCni
{ MjbgAH-
processErrorCode(responseCode); 55=YM'5]
return -2; //-2 represent access is error )_}xK={
} i?,\>LTG
0n\AUgVPF
h<qi[d4X
String sHeader; ^FZ9q
$"va8,
):fu]s"
for(int i=1;;i++) (-VH=,Md
{ m= %KaRI
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *\*]:BIe&v
//Utility.log(in.readLine()); L1&` 3a?pL
sHeader=httpConnection.getHeaderFieldKey(i); V(Cxd.u
if(sHeader!=null) 'r1X6?dJ
{ e}(8BF
if(sHeader.equals("Content-Length")) n6 wx/:
{ Z_>:p^id
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /JIVp_-p
break; z>b^Ui0
} O`Htdnu
} IsjN xBM
else Vddod
break; %.8(R &
} iH>b"H>
} {c7@`AV]
catch(IOException e){e.printStackTrace ();} 0^6}s1d_
catch(Exception e){e.printStackTrace ();} ONUa7
%&J`mq
u++a0>N
Utility.log(nFileLength); }H/94]~tH
*2/6fhI[p
Z{2QDjAI;
return nFileLength; OaY]}4tI$
} S_s;foT
D0Ls~qr
O#<S\66
//保存下载信息（文件指针位置） 0*j\i@
private void write_nPos() WGo ryvEx
{ Hi U/fi`
try{ I*pFX0+
output = new DataOutputStream(new FileOutputStream(tmpFile)); {;o54zuKf
output.writeInt(nStartPos.length); "9Br)3
for(int i=0;i<nStartPos.length;i++) .tsXQf
{ 3%u: c]-wF
// output.writeLong(nPos); |T-Ytuy8
output.writeLong(fileSplitterFetch.nStartPos); W k"_lJ
output.writeLong(fileSplitterFetch.nEndPos); (e9hp2m
} V'9OGn2v
output.close(); mXu";?2
} I]~s{I(EK
catch(IOException e){e.printStackTrace ();} 0:x+;R<P*w
catch(Exception e){e.printStackTrace ();} QRF:6bAxsL
} \2Kl]G(w%y
C*Qx
$>Gf;k
//读取保存的下载信息（文件指针位置） la_
private void read_nPos() lxBcO/
{ v4\ m9Pu4
try{ VotI5O $
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); nVGOhYn
int nCount = input.readInt(); lg@q} ]1
nStartPos = new long[nCount]; fUJe{C<H
nEndPos = new long[nCount]; k;.<DN
for(int i=0;i<nStartPos.length;i++) GB}X
{ wHQYBYKcd
nStartPos = input.readLong(); YLV$#a3
nEndPos = input.readLong(); Xg}~\|n
} NNRKYdp,
input.close(); ])WIw'L!
} (e3?--~b6
catch(IOException e){e.printStackTrace ();} XLm@, A[
catch(Exception e){e.printStackTrace ();} ">nFzg?Y
} d"+ _`d=`
`?T8NK
5zt5]zl'
private void processErrorCode(int nErrorCode) ;bq EfV0`2
{ ~$bQ;`,L
System.err.println("Error Code : " + nErrorCode); ;;LiZlf
} =[Tf9uQY
_3gF~qr
PU\@^)$
//停止文件下载 KpO%)M!/Z#
public void siteStop() {1GIiP-U
{ BFn}~\wzK
bStop = true; jLBwPI_g
for(int i=0;i<nStartPos.length;i++) -} +PE 4fh
fileSplitterFetch.splitterStop(); ,E4qxZC(X
\0l"9 B.
cp+eh
} iLFhm4.PO
} McU]U9:z
//负责部分文件的抓取 YFW0
**FileSplitterFetch.java `Y7&}/OM
*/ u8[jD^
package NetFox; vu)V:y
N,`<:'
{7FD-Q[tS
import java.io.*; hC2Ra "te)
import java.net.*; uvGFo)9q3
6j~'>w(F
+'?axv6e
public class FileSplitterFetch extends Thread { F}#=qBa[
FDRpK5cw
I*8_5?)g<
String sURL; //File URL j[y+'O
long nStartPos; //File Snippet Start Position +JL"Z4b@R}
long nEndPos; //File Snippet End Position m2Q#ATLW
int nThreadID; //Thread's ID O7T wM Yh
boolean bDownOver = false; //Downing is over RIxGwMi%
boolean bStop = false; //Stop identical -o0~xspF
FileAccessI fileAccessI = null; //File Access interface ,0[h`FN
gUxJ>~
8I=migaxP
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .e%B'
{ <lVW;l7
this.sURL = sURL; _p=O*$b.
this.nStartPos = nStart; s&zg!~@5b
this.nEndPos = nEnd; d[I}+%{[
nThreadID = id; tr\}lfK%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 F>A&L8
} c1p*}T
nA^UF_rD-
zWIC4:
public void run() W%RjjLJ@
{ $mG&4Y
while(nStartPos < nEndPos && !bStop) iw^(3FcP@C
{ `l95I7
8z,|N#
CEos`
try{ W.AN0N
URL url = new URL(sURL); C/Dc1sj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3YF*TxKx
httpConnection.setRequestProperty("User-Agent","NetFox"); <ib#PLRM
String sProperty = "bytes="+nStartPos+"-"; &Q"Ox{~W
httpConnection.setRequestProperty("RANGE",sProperty); M&iA^Wrs
Utility.log(sProperty); !&D&Gs
3M{/9rR[
ISuye2tExq
InputStream input = httpConnection.getInputStream(); bqAv)2
//logResponseHead(httpConnection); ?5!>k^q
dF%sD|<)
:jq
byte[] b = new byte[1024]; Yg6 f
int nRead; N8| ;X
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Td5;bg6Qy
{ NK+iLXC
nStartPos += fileAccessI.write(b,0,nRead); jnuovM!x~
//if(nThreadID == 1) *a7&v3X
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .^S#h (A
} Py[Z9KLX
CKv[E
*@r)3
Utility.log("Thread " + nThreadID + " is over!"); b_]14 v
bDownOver = true; &Q[Y&vNn
//nPos = fileAccessI.write (b,0,nRead); $b/oiy!=|3
} ~E=.*: 5(
catch(Exception e){e.printStackTrace ();} u"\HBbBx
} Q2)z1'Wv
} zF2GW
.4"9o%
}F1|& A
//打印回应的头信息 \*s'S*~
public void logResponseHead(HttpURLConnection con) EF?@f{YY$n
{ j|&?BBa9
for(int i=1;;i++) [e+"G <>
{ eGS1% [
String header=con.getHeaderFieldKey(i); n;0bVVMV
if(header!=null) 2!/_Xh
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2 fX-J
Utility.log(header+" : "+con.getHeaderField(header)); 95,y@~*]
else $Blo`'
break; \w!G
} n)w@\Uyc
} w<<G}4~u|
~\c]!%)o
HPAd@5d(
public void splitterStop() k, )7v
{ /I3#WUc;![
bStop = true; rHu#
} CE>RAerY
Yz0ruhEMk
6|m1z
} q79)nhC F
>+=)Q,|R
A\Q]o#U
/* (u-i{<
**FileAccess.java AG2iLictv
*//文件访问(定位，写) <L@0w8i`
package NetFox; 5@"&%8oeq0
import java.io.*; *Wv]DV=\
'2a}1?
gM20n^
public class FileAccessI implements Serializable{ g6$X {
S=^yJ6xJ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 . zvF!!z
RandomAccessFile oSavedFile; ^:K"Tv.=
long nPos; b7{)B?n
6pI=?g
!SIGzj
public FileAccessI() throws IOException 1`2n<qo
{ b5 YE4h8%
this("",0); )+Wx!c,mb
} H1f){L97wR
}%[TJ@R;
"-kb=fY
public FileAccessI(String sName,long nPos) throws IOException X3I\O,"I
{ dfGdY"&
oSavedFile = new RandomAccessFile(sName,"rw"); Lw?4xerLsb
this.nPos = nPos; <wxI>T}b
oSavedFile.seek(nPos); |x2>F
} r80w{[S$
8HdmG{7.
FZz\zp
public synchronized int write(byte[] b,int nStart,int nLen) too=+'<N</
{ Yva^JB
int n = -1; xj)*K%re
try{ &@c=$+#C
oSavedFile.write(b,nStart,nLen); oDTt+b
n = nLen; Vp\BNq_!s
} q*TH),)J
catch(IOException e) Zgt, 'T
{ eP|:b &
e.printStackTrace (); *f$mSI=
} .GM&]Hb
~!&WK,k6
z)=D&\HX
return n; #tKc!]m
} G6_Kid}"q
zFqH)/
RO=[Rr!
} /}-]n81m
3_B .W
,(}7 ST
/* @a)@1:=Rm
**SiteInfoBean.java {f3)!Pei`J
*/ 5Jd&3pO
package NetFox; cPi 3UjY~
Z$kff-Y4
bdk"7N
public class SiteInfoBean { ooreforr
1]aM)},
4~hd{8
private String sSiteURL; //Site's URL 2)h i(
private String sFilePath; //Saved File's Path E< "aUnI
private String sFileName; //Saved File's Name |8c3%jve
private int nSplitter; //Count of Splited Downloading File DGj:qd(
gpVZZ:~
8n?qm96
public SiteInfoBean() vXLiYWo
{//nSplitter的缺省值为5 $GNN*WmHw
//default value of nSplitter is 5 [!,&A{.!
this("","","",5); iKN~fGRc
} ZK1d3
1T!b#x4
Q}d6+C
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) L TZ3r/
{ y!u)q3J0&
sSiteURL= sURL; b%L8mX
sFilePath = sPath; {3@f(H m
sFileName = sName; d^mw&F)S
this.nSplitter = nSpiltter; |)* K#%j
F?\XhoJ3G
VUxuX5B3M
} d }=fJ
6x)7=_:0
9cp-Rw<tI
public String getSSiteURL() iagl^(s
{ q.U` mtS
return sSiteURL; J:Ea|tXK^
} ^=.R#zrc
F{0Z
%i{Z@
public void setSSiteURL(String value) ExeD3Zj
{ @X+m,u
sSiteURL = value; Bha#=>4FU
} z0+LD
<k!M+}a 9V
}(A`aB_
public String getSFilePath() GPz0qK
{ "s]r"(MX
return sFilePath; FeoI+KA
} ~U(`XvR\4
`ltc)$
Q)c3=.[>
public void setSFilePath(String value) \@;$xdA$
{ Z<L}ur
sFilePath = value; M<^]Ywq*p
} r+n0M';0
V 6I77z
5xC4lT/U
public String getSFileName() $9+|_[ ]v.
{ YbtsJ <w
return sFileName; w^z5O6
} }A jE- K{
g%Bh-O9\
7f|8SB
public void setSFileName(String value) M2H +1ic
{ "@^Pb$BLY
sFileName = value; 01=nS?
} Q2yD4>qy
}py)EI,U
jq%%|J.x
public int getNSplitter() ~MWI-oK
{ %O6r
return nSplitter; 9d&@;&al
} \]C_ul'
XSk*w'xO
B@cC'F#G
public void setNSplitter(int nCount) }`KK
{ fF6bEJl3
nSplitter = nCount; mi[t1cN)=
} ]1hyvm3
} Gyx4}pV
&1/OwTI4J
S[ch/
/* OfG/7pw5%B
**Utility.java &!P' M
*/ 8\WV.+
package NetFox; ;~D$rT
<fHJ9(5$V
U!d|5W.{Q
public class Utility { Cj%n?-
U#V&=~-
\SSHjONX
public Utility() Gj_7wP$
{ [ Y+Ta,
j,n\`7dD$
{W+IUvn
} _'8P8T&
XHU\;TF
//线程睡眠 mT:NC'b<9
public static void sleep(int nSecond) Ez8k.]qu
{ L4DT*(;!E
try{ ?(Se$iTZ
Thread.sleep(nSecond); Hf/ZaBn
} 8)lrQvZ
catch(Exception e) 3Fb9\2<H
{ AH{#RD
e.printStackTrace (); 6k_Uq.<X
} zmU@ k
} 1 |
lihIPMU
//日志 ;6eBfMhL
public static void log(String sMsg) HYg! <y
{ Rk,'ujc
System.err.println(sMsg); xa.tH)R
} 7fI2b,~
.TMLg(2hgv
V408uy-M
public static void log(int sMsg) mC0_rN^Aj
{ @ ]40xKF
System.err.println(sMsg); 4O{G^;
} AsD$M*It
} dz?On\66
&~Pk*A_:
FDFwx|
/* c]h@<wnv
**TestMethod.java j7U&a}(
*/ ?&'Kw>s@
package NetFox; m/Erw"Z
qu1+.z=|
35Fxzj $
public class TestMethod { /ej[oR
U shIQh
iciKjXJ:
public TestMethod() #i.,+Q
{ ///xx/weblogic60b2_win.exe ZNne 8
try{ %3O))Ug5
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); DuNindo8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); D2g/P8.<A
SiteFileFetch fileFetch = new SiteFileFetch(bean); "={*0P
fileFetch.start(); 8\"Gs z
} 6I: 6+n
catch(Exception e){e.printStackTrace ();} =[8K#PZ$w
y>.t[*zT
RyP MzxV
} gyMHC{l/B
JO`r)_
^*i0~_
public static void main(String[] args) 63 'X#S
{ >s 6ye
new TestMethod(); #bBh. ^
} od{\z
} R)BXN~dQ
点击下载更多相关资料