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)); L{Epkay,{
} tTe\#o`
for(int i=0;i<nEndPos.length-1;i++) &CF74AN#
{ cysYjuI i
nEndPos = nStartPos[i+1]; :gVz}/C.@
} il\#R%';5
nEndPos[nEndPos.length-1] = nFileLength; m!a<\0^
} %FLz}QW*
} W}+Q!T=
O[3J Px
4vPQuk!
//启动子线程 Fe%Q8RIh_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; aePhtQF
for(int i=0;i<nStartPos.length;i++) #JeZA0r5
{ oHB51< }
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `;*%5WD%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), SoS[yr
nStartPos,nEndPos,i); %#2[3N{
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J:)Q)MT24:
fileSplitterFetch.start(); x "]%q^x
} 6cVaO@/(
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fyYT#r
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); c^}gJ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", yAG4W[
nEndPos = " + nFileLength); h"Yi'
// fileSplitterFetch[nPos.length-1].start(); DY^q_+[V
ypwVzCUG
Duj9PV`2
//等待子线程结束 8fTuae$^
//int count = 0; NtkEb :
//是否结束while循环 .<^dv?@
boolean breakWhile = false; G<9MbMG
FgrOZI;_
7&/iuP$.
while(!bStop) 9yajtR
{ DoX#+ 07u4
write_nPos(); i>_V?OT#5
Utility.sleep(500); +*a:\b"fx
breakWhile = true; z(iB$;M
X8<<;?L
b)(#/}jMkD
for(int i=0;i<nStartPos.length;i++) @G^]kDFM{
{ ;S"^O AM
if(!fileSplitterFetch.bDownOver) \A*#a9"
{ mWsVOf>g
breakWhile = false; POfvs]
break; ;gTdiwfgZ=
} 4Wk/^*?
} #q9jFW8
if(breakWhile) [ahD%UxO5
break; K SDo)7`
^F5[2<O/!
aRdk^|}
//count++; r^n%PH<
//if(count>4) ]Hc`<P
// siteStop(); o?b$}Qrl
} YDyOhv
|s+[489g'6
&sh %]o8
System.err.println("文件下载结束！"); 0SwWLq
} #n]js7
catch(Exception e){e.printStackTrace ();} 'D-eFJ5
} xV}E3Yj2#
!3v!BJ#+,&
}?$d~]t)
//获得文件长度 epJVs0W
public long getFileSize() fBR,Oneo
{ I{JU<A,&
int nFileLength = -1; 8GN0487H
try{ _S{HVc
URL url = new URL(siteInfoBean.getSSiteURL()); z^gf@r
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &=nwb4
httpConnection.setRequestProperty("User-Agent","NetFox"); Uxn_nh
fJn;|'H!
;3h[=hyS
int responseCode=httpConnection.getResponseCode(); D!Owm&We
if(responseCode>=400) Ry,_%j3
{ aU<0<Dx
processErrorCode(responseCode); ]BP"$rs
return -2; //-2 represent access is error F]N9ZWn/
} NYM$0v`0YK
$fPf/yQmC
,6~c0]/
String sHeader; _]E"hr6a
ah>;wW!6/
,u-i9`B
for(int i=1;;i++) fCJ:QK!
{ iS&fp[Th
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8&qCH>Cf
//Utility.log(in.readLine()); `E8m>q Ss
sHeader=httpConnection.getHeaderFieldKey(i); -d[9mS
if(sHeader!=null) 6{8qATLR
{ K%[Rv#>;q|
if(sHeader.equals("Content-Length")) vE;`y46&r
{ BLgmFE2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Y 6K<e:Y
break; B%6>2S=E
} 1?]Gl+}
} pR4{}=g,
else Yn+/yz5k_
break; X<Rh-1$8F
} 4};iL)
} Y\(Q
catch(IOException e){e.printStackTrace ();} q{n~v>wU
catch(Exception e){e.printStackTrace ();} q@~N?$>
-A(]",*J
1 9$ufod
Utility.log(nFileLength); y)t< r
*^bqpW2$q
_*0!6?c
return nFileLength; w{#K.dx
} F2:+i#lE
;El"dqH
)a.w4dH
//保存下载信息（文件指针位置） ;26a8g(
private void write_nPos() e-sMU
{ _M8Q%
try{ -_[n2\|we)
output = new DataOutputStream(new FileOutputStream(tmpFile)); dB ?+-aE
output.writeInt(nStartPos.length); E}-Y@( [
for(int i=0;i<nStartPos.length;i++) Wo&MHMP
{ N8m|Y]^H#
// output.writeLong(nPos); 12gcma}
output.writeLong(fileSplitterFetch.nStartPos); 5u'"m<4
output.writeLong(fileSplitterFetch.nEndPos); ^Jcs0c @\
} y&-wb'==p
output.close(); n,hHh=.Fu
} {xi$'r
catch(IOException e){e.printStackTrace ();} pa N )t
catch(Exception e){e.printStackTrace ();} 1Cki}$k@
} ]sE~gro
G#ZU^%$M,
uhSRl~tn
//读取保存的下载信息（文件指针位置） j2}C
private void read_nPos() {wih)XNY
{ =>-:o:Cu{
try{ JBtcl#|
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); SSYE&
int nCount = input.readInt(); fKY6stJE
nStartPos = new long[nCount]; eLJW
nEndPos = new long[nCount]; _Ft4F`pM
for(int i=0;i<nStartPos.length;i++) -^=gQ7f9
{ ~b+4rYNxU_
nStartPos = input.readLong(); }o0R`15dA
nEndPos = input.readLong(); i64a]=
} "1$OPt5
input.close(); {(U?)4@
} 8`Q8Mct$<
catch(IOException e){e.printStackTrace ();} a)^f`s^aa
catch(Exception e){e.printStackTrace ();} }i!hzkK#
} *>h"}e41
p 2It/O
x[U/ 8#f&
private void processErrorCode(int nErrorCode) "X4OUk
{ H{ p
System.err.println("Error Code : " + nErrorCode); ;| ##~Y.9
} T~J6(,"
R(@B4M2
Z@>hN%{d+g
//停止文件下载 wASgdGoy
public void siteStop() kzny4v[y
{ ?wt%e;
bStop = true; $YSAD\a<
for(int i=0;i<nStartPos.length;i++) )WF]v"t
fileSplitterFetch.splitterStop(); e7T"?s
cq>{
P95U{
} N%v}$58Z
} mjO4GpG3
//负责部分文件的抓取 k"Y9Kc0XoU
**FileSplitterFetch.java U']DB h
*/ 9G_bM(q'^2
package NetFox; 8VQJUwf;
Gu}|CFL\
mRZC98$ @r
import java.io.*; Y*/:IYr`
import java.net.*; S9S8T+
.0kltnB
K:gxGRE
public class FileSplitterFetch extends Thread { Vz6p^kMB
.Qm"iOyM
5+\[x`
String sURL; //File URL eu@hmR8T
long nStartPos; //File Snippet Start Position |s`j=<rNQI
long nEndPos; //File Snippet End Position }u:@:}8K
int nThreadID; //Thread's ID <^snS,06
boolean bDownOver = false; //Downing is over \W=~@k
boolean bStop = false; //Stop identical ~CIA6&
FileAccessI fileAccessI = null; //File Access interface wvBx]$SC
fDt#<f 4;
6My=GByC
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException bO]^TRaiJ
{ !#j y=A
this.sURL = sURL; &b8Dy=#
this.nStartPos = nStart; DP ,owk
this.nEndPos = nEnd; 4+e9:r]
nThreadID = id; dP63bV
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [[2Zcz:
} n[8ju,=
smvIU0:K
Tj7OV}:
public void run() teH.e!S
{ )w(-Xc?P
while(nStartPos < nEndPos && !bStop) S+Z_Qf
{ GEj/Z};;[b
(jd)sf6Tj[
by!1L1[JTt
try{ 1"?3l`i
URL url = new URL(sURL); Sm(X/P=z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &6<>hqR^
httpConnection.setRequestProperty("User-Agent","NetFox"); 1)yEx1
String sProperty = "bytes="+nStartPos+"-"; 4XpW#>
httpConnection.setRequestProperty("RANGE",sProperty); :tU&d(8
Utility.log(sProperty); -9TNU7^
\H|tc#::{
H_RV#BW&
InputStream input = httpConnection.getInputStream(); l/0"'o_0v#
//logResponseHead(httpConnection); 11t+ a,fM
.RFijr
DuX7
byte[] b = new byte[1024]; {`?C5<r
int nRead; *'4+kj7>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 95LZG1]Rb
{ =?g26>dYo
nStartPos += fileAccessI.write(b,0,nRead); r LQBaT7t#
//if(nThreadID == 1) CeQL8yJ;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *`$Y!uzG:\
} q-gp;Fm
dS]TTU1
,l/~epx4v)
Utility.log("Thread " + nThreadID + " is over!"); QY2/mtI
bDownOver = true; "#,]`ME;
//nPos = fileAccessI.write (b,0,nRead); 0,$eiY)u$
} ~2u~}v5m7
catch(Exception e){e.printStackTrace ();} {=mf/3.r
} K"4m)B~@Y
} Lt`d {s
uc;1{[5`1q
\GhL{Awv&a
//打印回应的头信息 0'8_:|5
public void logResponseHead(HttpURLConnection con) y"zgpqJ
{ K;kaWV
for(int i=1;;i++) Hl-!rP.?0
{ ?^I\e{),c
String header=con.getHeaderFieldKey(i); #-vuY#gs
if(header!=null) _2uRY
//responseHeaders.put(header,httpConnection.getHeaderField(header)); !bs{/?
Utility.log(header+" : "+con.getHeaderField(header)); V&nTf100
else .m%/JquMFM
break; L3}n(KAJj
} M~%~y`D^
} "<['W(
}]O* yFR{j
qJV2x.!
public void splitterStop() 'YQ^K`lV
{ ;Z>u]uK4+
bStop = true; 1EE4N\
} 3sr>?/>:
`;KU^dH
u@QP<[f
} aY`qbJy
MI8f(ZJK5
ZqT8G
/* R\DdU-k
**FileAccess.java J)(KGdk
*//文件访问(定位，写) t6-He~
package NetFox; fKEZlrw
import java.io.*; /$a>f>EJ
)}ygzKEa
}U <T>0
public class FileAccessI implements Serializable{ uWm,mGd9
st~ 1[in
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 F3d: W:^_
RandomAccessFile oSavedFile; Y2lBQp8'|
long nPos; +,oEcCi
Iw@ou
n1 k2<BU4b
public FileAccessI() throws IOException K>%}m,
{ +5:Dy,F=
this("",0); ~V#MI@]V~
} a^:on?:9
aqL#g18
3JhT
public FileAccessI(String sName,long nPos) throws IOException f@JMDJ
{ UqVcN$^b
oSavedFile = new RandomAccessFile(sName,"rw"); GM]" $
this.nPos = nPos; q{4W@Um-
oSavedFile.seek(nPos); Oz8"s4Y7
} </xz V<Pi
K|n%8hRy
jhRg47A
public synchronized int write(byte[] b,int nStart,int nLen) R#"LP7\
{ <4lR
int n = -1; B=<>OYH
try{ 9, A(|g
oSavedFile.write(b,nStart,nLen); =*paa
n = nLen; +M )ep\j
} (L`7-6e(Ab
catch(IOException e) 18`YY\u(
{ ?E>(zV1D/
e.printStackTrace (); 5(9SIj^O
} 8{0=tOXx{
FYwMmb ~3
d6(R-k#B
return n; FYOQ}N
} Bh`Y?S
F_^)zss
0`WjM2So
} JAt$WW{
Rs$fNW@P
8|]r>L$Wk
/* o7:~C]
**SiteInfoBean.java c>SFttbU
*/ 5Z8Zb.
package NetFox; +qPpPjG;
,\){-H/n
J#1-Le8@
public class SiteInfoBean { C0f<xhp?j
Bqcih$`BVU
cd&^ vQL8
private String sSiteURL; //Site's URL ON,sN
private String sFilePath; //Saved File's Path z (1zth
private String sFileName; //Saved File's Name dM-qd`
private int nSplitter; //Count of Splited Downloading File 9+irf^D`O
`EBI$;!
!xE/
public SiteInfoBean() _cRCG1CJ
{//nSplitter的缺省值为5 st_.~m!/
//default value of nSplitter is 5 \*a7o GyH>
this("","","",5); ,(&p"O":
} >Bw<THx
x]6-r`O7r
|\}&mBR
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) w"PnN
{ f6of8BOg
sSiteURL= sURL; b(E}W2-t
sFilePath = sPath; @PQ% xcOC7
sFileName = sName; Os90fR
this.nSplitter = nSpiltter; kA.U2
(&Kv]--
m{v*\e7P
} 5SB!)F]
R^p'gQc$
\X*Es.;|x
public String getSSiteURL() xmM!SY>
{ 3-=f@uH!
return sSiteURL; &g;&=<#I
} {+3 `{34e
h]+UK14m
*jf%Wj)0M
public void setSSiteURL(String value) a<NZC
{ W>E/LBpE4
sSiteURL = value; +!~"ooQZh
} K]{x0A
@%^JB
+nIjW;RU
public String getSFilePath() LJ8 t@ui
{ gh?3[q6
return sFilePath; Nc da~h Q
} g7UZtpLTm
4\_~B{kzZ
k4E2OyCFoJ
public void setSFilePath(String value) '+s?\X4VC
{ R9&3QRW|
sFilePath = value; 4@mK:v%
} /g]NC?
K\trT!I
3 0.&Lzz
public String getSFileName() QomihQnc
{ : MEB] }
return sFileName; /ucS*m:<x
} 5(\H:g\z
|Wg!>g!
6uTFgSqZ
public void setSFileName(String value) #iiXJnG
{ 5%jy7)8C
sFileName = value; n~Yr`5+Z
} rj ] ~g
$~,J8?)(z
c;B:o
public int getNSplitter() FokSg[)5
{ (&KBYiwr
return nSplitter; 3sK^ (
} dFl8'D
uqsVq0H
R*`=Bk0+
public void setNSplitter(int nCount) 2PC:F9dh\
{ 4c]=kbGW
nSplitter = nCount; ( }RJW:
} 3+/^
} u- }@^Y$M
Bfu/w
VvUP;o&/
/* zN&m-nrw
**Utility.java <'N~|B/yZ
*/ N[zR%(YS
package NetFox; [OYSNAs*y
8xb({e4
0B]c`$"aD
public class Utility { rNoCmNm
]p@q.P
)B9/P>c
public Utility() 5D <
{ MAcjWb~f
ELZ@0,
@x@wo9<Fc
} YM,UM>
bcYGkvGbO
//线程睡眠 _)Ad%LPsd7
public static void sleep(int nSecond) 2[CHiB*>
{ rM`z2*7%d
try{ H-qbgd6&>R
Thread.sleep(nSecond); jfU$qo!gi
} 717OzrF}A?
catch(Exception e) }1mkX\wWP
{ .^wBv 'Y
e.printStackTrace (); = G>Y9Sc
} lxfv'A
} ?BRZ){)
2t;3_C
//日志 qV)hCc/ ~
public static void log(String sMsg) ~^J9v+
{ @ek8t2??x
System.err.println(sMsg); +O4//FC-"
} zmhAeblA
w$0*5n>)
[ e#[j{
public static void log(int sMsg) 6t{G{ ]
{ 4xF}rm
System.err.println(sMsg); cp&1yB
} ge]Z5E(1
} *>k6n5%
KP_7h/e
zHD8\*
/* u`"Y!*[ -
**TestMethod.java qGi\*sc>x
*/ d~KTUgH'<
package NetFox; GA"vJFQ
0v|qP
$+ORq3
public class TestMethod { uMjL>YLq{?
qu0q LM
i(4.7{*
public TestMethod() gNC'kCx0c
{ ///xx/weblogic60b2_win.exe z+c'-!e/
try{ mGoNT
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); EX@Cf!GjN
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |fY#2\)Yx
SiteFileFetch fileFetch = new SiteFileFetch(bean); P6)d#M
fileFetch.start(); oQR?H
} t!59upbN}3
catch(Exception e){e.printStackTrace ();} .Ms$)1
R@KWiV
xLP8*lvy
} 24*3m&fA*K
t$PJ*F67M
(ZP e{;L.
public static void main(String[] args) tm.&k6%
{ p.5 *`, )
new TestMethod(); _6->D[dB
} ~FVbL-2
} ]YY4{E(9d
点击下载更多相关资料