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)); Gz,?e]ZV
} eq!>~: #
for(int i=0;i<nEndPos.length-1;i++) >$RQ
{ Pd"=&Az|
nEndPos = nStartPos[i+1]; z3bRV{{YqN
} nN]GO}
nEndPos[nEndPos.length-1] = nFileLength; 1j!LK-
} w I7iE4\vz
} 1_of;=9V
oE H""Bd
9[5qN!P;y
//启动子线程 jgW-&nK!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; vo]!IY
for(int i=0;i<nStartPos.length;i++) `;7eu=
{ 6Bop8B
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `u't
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~fV\ X*
nStartPos,nEndPos,i); ^]cl:m=*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Jx jP'8
fileSplitterFetch.start(); +~x'1*A_
} %lbDcEsf9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A%[BCY_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); s.#%hPX{
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", JdK'~-L
nEndPos = " + nFileLength); L*QX21@wC
// fileSplitterFetch[nPos.length-1].start(); L2,.af6+
KmYSYNr@,
cUH.^_a
//等待子线程结束 ,'nd~{pX"(
//int count = 0; 3bd(.he2u
//是否结束while循环 RnaxRnXVR
boolean breakWhile = false; d5z=fH9
2&,jO+BqE@
tpY]Mz[J
while(!bStop) nc2=S^Fqu
{ 9*&c2jh
write_nPos(); /TndB7l"3
Utility.sleep(500); [XKudw%
breakWhile = true; aob+_9o
nZbINhls
W0 n?S "
for(int i=0;i<nStartPos.length;i++) "PD^]m
{ kF@Z4MB}yr
if(!fileSplitterFetch.bDownOver) VL?sfG0
{ Mjon++>Z
breakWhile = false; wwuM!Z+
break; k Xg&}n7
} Lhz*o6)
} sc0.!6^'V
if(breakWhile) =.48^$LWx
break; '-l.2IUyT
q^w@l
CQANex4&\
//count++; $SOFq+-T
//if(count>4) L7`=ec<
// siteStop(); ]J(BaX4
} KL<,avC/
Ym8 V)
D^Gs_z$['
System.err.println("文件下载结束！"); F%tV^$%
} )yt_i'D}
catch(Exception e){e.printStackTrace ();} ~z kzuh
} gJZH??b
bl3?C
$ o }
//获得文件长度 \V_Tc`
public long getFileSize() T\wfYuc&X
{ KbSE=3
int nFileLength = -1; +Zg@X.z
try{ cFZcBiw
URL url = new URL(siteInfoBean.getSSiteURL()); L+X:M/)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )vsX (/WU
httpConnection.setRequestProperty("User-Agent","NetFox"); "OO)m](w
jAcrXB*
PrKH{nyJk
int responseCode=httpConnection.getResponseCode(); W5Uw=!LdEY
if(responseCode>=400) =o5|W'>`
{ `PUGg[Zx^
processErrorCode(responseCode); S aH':UN
return -2; //-2 represent access is error "}x%5/(
} &~aS24c
`x]`<kS;
*6bO2LO"
String sHeader; -hY@r 7y
}3}H}
aJ"m`5]=%
for(int i=1;;i++) |[Rlg`TQ;*
{ SaIY-PC
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |E9'ii&?B
//Utility.log(in.readLine()); o* ~aB_
sHeader=httpConnection.getHeaderFieldKey(i); f}t8V% ^E
if(sHeader!=null) <2SWfH1>
{ 7tP%tp ez
if(sHeader.equals("Content-Length")) lv>^P>S(O
{ bn%4s[CVb4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +P=IkbxAO
break; eBWgAf.k
} yu>o7ie+;Y
} o1?S*
else )~0TGy|
break; 4Ql9VM%y
} b+CJRB1
} lc$wjK[w[
catch(IOException e){e.printStackTrace ();} 5HaI$>h6
catch(Exception e){e.printStackTrace ();} c;Gf$9?iC
c`@";+|r
al"=ld(
Utility.log(nFileLength); L++qMRk9
[jv+Of IZ
kMx)G]
return nFileLength; ek"Uq RY
} zP&D
tv_&PIu]L
bXi!_'z$
//保存下载信息（文件指针位置） P~M[i9 V
private void write_nPos() v!W{j&N
{ PX*}.L *x
try{ .1+I8qj
output = new DataOutputStream(new FileOutputStream(tmpFile)); v5\5:b{/
output.writeInt(nStartPos.length); V}Ee1C
for(int i=0;i<nStartPos.length;i++) aJQzM
{ \10KIAQ
// output.writeLong(nPos); LS$zA>:
output.writeLong(fileSplitterFetch.nStartPos); ` {qt4zd0
output.writeLong(fileSplitterFetch.nEndPos); [MuZ^'dR
} q BIekQT
output.close(); HbRvU}C1
} Z2t\4|wr:
catch(IOException e){e.printStackTrace ();} ? G`6}NP
catch(Exception e){e.printStackTrace ();} npd:aGx
} )8!*,e=4
uM\5GK
S=gby
//读取保存的下载信息（文件指针位置） G c\^Kg^#
private void read_nPos() ]q~bi<E9W
{ Qvty;2$o@
try{ {a__/I>)
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _, E/HAX
int nCount = input.readInt(); o*Xfgc
nStartPos = new long[nCount]; !1=*"H%t
nEndPos = new long[nCount]; z-qbe97
for(int i=0;i<nStartPos.length;i++) %E5b}E#
{ ;:&|DN3;
nStartPos = input.readLong(); ZS%W/.?
nEndPos = input.readLong(); j XH9Pq4
} z)(W x">
input.close(); *NG\3%}%|@
} |RXQ_|
catch(IOException e){e.printStackTrace ();} /wax5FS'I,
catch(Exception e){e.printStackTrace ();} x5CMP%}d
} lWecxD$
|Iwglb!k
*`rfD*
private void processErrorCode(int nErrorCode) xr{Ym99E$
{ @TQ/Z$y
System.err.println("Error Code : " + nErrorCode); 9|lLce$
} d!UxFY@
j!w{
ggL/7I(
//停止文件下载 P6O\\,B1A
public void siteStop() 33EF/k3vW
{ YrJUs]A
bStop = true; eZ+6U`^t
for(int i=0;i<nStartPos.length;i++) K2yu}F^}
fileSplitterFetch.splitterStop(); ^Fh*9[Zf$
swxX3GR
i6KB\W2
} lOp.cU
} oX8EY l
//负责部分文件的抓取 *g,ls(r\[
**FileSplitterFetch.java lKw-C[
*/ 9OV@z6
package NetFox; a_V\[V{R=
tc0;Ake-&
~f(5l.
import java.io.*; `hZh}K^
import java.net.*; g{Al:}u>
8W{M}>;[9
Gk{ 'U
public class FileSplitterFetch extends Thread { w8w0:@0(
W`_JERo
@b,H'WvhfS
String sURL; //File URL ?W{+[OXs
long nStartPos; //File Snippet Start Position Zs />_w}
long nEndPos; //File Snippet End Position s`_EkFw>Gl
int nThreadID; //Thread's ID \^*:1=|7u]
boolean bDownOver = false; //Downing is over T2MC`s|`
boolean bStop = false; //Stop identical ;ND$4$
FileAccessI fileAccessI = null; //File Access interface 2+rT .GFc
J`U]Ux/L
/iFn=pk1?
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =S`h/fru
{ Yi%lWbr
this.sURL = sURL; x*7A33@i
this.nStartPos = nStart; \jwG*a
this.nEndPos = nEnd; @01.Pd
nThreadID = id; 7K\v=
fileAccessI = new FileAccessI(sName,nStartPos);//定位 EL$DvJ~
} 1`K-f m)
Y7.+ Ma#|
YWK0.F,8a
public void run() O~*i_t*i9{
{ zsXgpnlHT
while(nStartPos < nEndPos && !bStop) lH4Nbluc^
{ f?UI+TU
>+a\BK"k
PaI\y!f
try{ 7HDc]&z
URL url = new URL(sURL); o~~;I
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); * @4@eQF
httpConnection.setRequestProperty("User-Agent","NetFox"); ^YLC{V
String sProperty = "bytes="+nStartPos+"-"; V1]GOmXz
httpConnection.setRequestProperty("RANGE",sProperty); vTK%4=|1}!
Utility.log(sProperty); /yG34) aB
Ic2?1<IZA
{$z54nvw$
InputStream input = httpConnection.getInputStream(); 5G`HJ6
//logResponseHead(httpConnection); :hZM$4
8gP1]xD
'5BD%#[
byte[] b = new byte[1024]; ,ErfTg&^
int nRead; _"1RidhH
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =xo0T 6
{ eM<N?9s
nStartPos += fileAccessI.write(b,0,nRead); i//H5D3
//if(nThreadID == 1) !zX()V
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,m=G9QcN
} kEDpF26!
$X#y9<bW
vha9,5_
Utility.log("Thread " + nThreadID + " is over!"); SboHo({5VA
bDownOver = true; =P(*j7=
//nPos = fileAccessI.write (b,0,nRead); 4-yK!LR
} Uj(0M;#%o+
catch(Exception e){e.printStackTrace ();} h^\vk!Q-d
} 2<@2_wSJ
} CPOHqK`k
FgH7YkKrD
gHe:o`
//打印回应的头信息 =Wcvb?;*
public void logResponseHead(HttpURLConnection con) 7 9tE
{ j9+4},>>CU
for(int i=1;;i++) TPN+jK
{ KnG7w^
String header=con.getHeaderFieldKey(i); )=5&Q
if(header!=null) MNu0t\`p4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >jI.$%L$
Utility.log(header+" : "+con.getHeaderField(header)); s)E \
else 3k1e
break; sycAAmH<
} JXc.?{LL
} #LasTN9
4'O,xC
?4b0\ -
public void splitterStop() cwmS4^zt8
{ y\skke]
bStop = true; dbby.%
} {M**a
EOB8|:*
"`% ,l|D
} `dvg5qQ
yx]9rD1cz
PJ5}c!o[
/* q94;x|63
**FileAccess.java Jq/itsg
*//文件访问(定位，写) 11oNlgY&
package NetFox; &aRL}#U
import java.io.*; flmQNrC.8
Fl`U{03
#gC[L=01
public class FileAccessI implements Serializable{ ]rv\sD`[
E{\CE1*
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 q<:8{Y|
RandomAccessFile oSavedFile; -pC'C%Q
long nPos; ~q ^o|?
aC,adNub
P73GH
public FileAccessI() throws IOException _LaG%* R6
{ !UoA6C:
this("",0); ?#z$(upQ
} So1TH%
\GL] I.
G0 )[(s
public FileAccessI(String sName,long nPos) throws IOException ,`HweIq(
{ +pR,BjY
oSavedFile = new RandomAccessFile(sName,"rw"); LSC[S:
this.nPos = nPos; 8B GZ
oSavedFile.seek(nPos); >?@5>wF
} AX v q~XE
5&n:i,
aF 2vgE\
public synchronized int write(byte[] b,int nStart,int nLen) rDWAZ<;;
{ B/4M;G~
int n = -1; ^{}G4BEY
try{ Al^tM0T^
oSavedFile.write(b,nStart,nLen); vFk@
n = nLen; u !BU^@P
} $]DuO1H./
catch(IOException e) hi"C<b.
{ PLz{EQ[cV
e.printStackTrace (); }h^ fX
} 0 PYYG
+ +L7*1t
sx#O3*'>1
return n; b=EI?XwJ
} Y(Qb)>K
*HD(\;i-$
?g ,s<{
} 4~}NB%,
]'pfw9"f~
wH|%3@eJ
/* ^&<M""Z
**SiteInfoBean.java U,U=udsi
*/ %NkiYiA
package NetFox; OL\-SQ&
Ic&~iqQ
gfggL&t(
public class SiteInfoBean { fK7 ?"^`/
lj]M 1zEz&
5~h)pt47
private String sSiteURL; //Site's URL g"/n95k<
private String sFilePath; //Saved File's Path ->I.D?p
private String sFileName; //Saved File's Name |cC3L09
private int nSplitter; //Count of Splited Downloading File V=ll 9M
sK%b16#
RFbf2s\t
public SiteInfoBean() 0o8`Y
{//nSplitter的缺省值为5 ' wl})
//default value of nSplitter is 5 GSRf/::I}4
this("","","",5); bVcJ/+Yx|
} RZxh"lIo
#f(a,,Uu'
S5JMt;O
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8~T}BC
{ Pjh;;k|V
sSiteURL= sURL; &~eCDlX/
sFilePath = sPath; J0Yb_(w
sFileName = sName; "vk]y
this.nSplitter = nSpiltter; V~PGmn[V
-+){;,
Ho(MO!(
} !Mw/j`*
'Qt[cW
-Jd7
public String getSSiteURL() =RUy4+0>F
{ iJOoO"Ai
return sSiteURL; GipiO5)1C
} ;jxX/c
lfBCzxifC
8T"L'{ggWB
public void setSSiteURL(String value) :#vA5kC
{ kt Z~r. +
sSiteURL = value; MVMJl">
} ^%*qe5J
g Nz
~V(>L=\V;
public String getSFilePath() Q=!QCDO(
{ (f"Qz~R|6_
return sFilePath; ();Z,A
} %o9mG<.T
zecM|S_
53/$8=
public void setSFilePath(String value) oBmv^=cH
{ bBINjs8C_
sFilePath = value; tY#&_%W
} s]yZ<uA
C=;}7g
yq, qS0Fo
public String getSFileName() &7kLSb&|;
{ 0F uj-q
return sFileName; 8Ud.t=2
} oTk\r$4eb
y-@`3hYM@
y=8KNseW|
public void setSFileName(String value) NjS<DzKhK
{ Bph(\= W
sFileName = value; <> HI(6\@Z
} =Q;dYx%I5
=WF@S1
W SvhC
public int getNSplitter() TH>uL;?=
{ ;U0w<>4L
return nSplitter; z__{6"^
} 9XUYy2{G
rU>l(O'b
&B8x0 yi
public void setNSplitter(int nCount) Lz9|"F"V
{ M$v\7vBgO!
nSplitter = nCount; }K.)yv n
} ER`;0#3[9u
} Ye^#]%m
!K.)Qr9V
CC6]AM(i
/* UM1h[#?&V)
**Utility.java |v>W
*/ cor!Sa>
package NetFox; c8l\1ce?7
4\U"e*
rJ4A9d3:
public class Utility { EwfL.z
aE]RVyG@L
^AwDZX
public Utility() 9-Qu5L~
{ &)Vuh=
fn//j7 j
xs)SKG*
} skLr6Cs|
uq!d8{IMu
//线程睡眠 LqQ&4I
public static void sleep(int nSecond) UWgPQ%}
{ 2ak*aI
try{ 30cb+)h(
Thread.sleep(nSecond); s|Vbc@t
} mnYzn[d3U
catch(Exception e) x50ZwV&j
{ r+k~%5Ff~
e.printStackTrace (); t%s(xz#1
} K}dvXO@=|c
} !5zj+N
p?<T _9e
//日志 U)S!@2(4
public static void log(String sMsg) d?GB#N|+g
{ dr=h;[Q'
System.err.println(sMsg); 8}OII\
} 35#"]l"
@ojV8
8{%[|Ye
public static void log(int sMsg) -[A=\]RfJ
{ *edhJUT
System.err.println(sMsg); qAVZ&:#
} oe1$;K>.7
} "&TN}SBW
HqKD]1
'_M"yg6d
/* D"s ]dQ$r
**TestMethod.java L%[b6<
*/ BWG#W C
package NetFox; -*0U&]T
#7,;/rtO7
5ma(~5
public class TestMethod { ":Ll.=!
a*UxRi8
/c52w"WW
public TestMethod() _*dUH5
{ ///xx/weblogic60b2_win.exe #s]`jdc
try{ CW;=q[+w
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); p V`)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); t8z=R6zX
SiteFileFetch fileFetch = new SiteFileFetch(bean); Q$=X ?{
fileFetch.start(); 0r'<aA`=I
} NR0fxh
catch(Exception e){e.printStackTrace ();} 5(&'/U^
0X4%Ccs
:x@j)&
} ^@n?&
-|3feYb'
)2y# cM*
public static void main(String[] args) v?qU/
{ )_Wo6l)i
new TestMethod(); KMogwulG
} Zdll}nO"E
} dhmZ3~cW>
点击下载更多相关资料