http断点续传简单实现（java)

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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)); VX>_Sps
} yRgo1ow]
for(int i=0;i<nEndPos.length-1;i++) vuAAaKz
{ g|+G(~=e|
nEndPos = nStartPos[i+1]; 17 j7j@s)
} ]&r/H17
nEndPos[nEndPos.length-1] = nFileLength; N{q'wep
} -d[x09
} S`6'~g
V)a6H^l
& 9?vQq|%
//启动子线程 C8t+-p
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )Z;Y,g
for(int i=0;i<nStartPos.length;i++) qC6Q5F
{ w}(xs)`num
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [p7le8=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !t_,x=
nStartPos,nEndPos,i); DC$ S. {n
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tTmFJ5
fileSplitterFetch.start(); C$%QVcf
} UfkRY<H
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #|CG %w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); PO}Q8Q3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ow$#kQ&R O
nEndPos = " + nFileLength); @O3w4Zs
// fileSplitterFetch[nPos.length-1].start(); w_{z"VeD
+}Q4 g]M8
c:$:j,i}
//等待子线程结束 #mM&CscE
//int count = 0; oVhw2pKpM
//是否结束while循环 4sJx_Qi
boolean breakWhile = false; J%A`M\
\hq8/6=4s
sZbzY^P
while(!bStop) O%)9tFT
{ VAthQ<
write_nPos(); +<q^[<pS
Utility.sleep(500); B!N807
breakWhile = true; NrU-%!Aw
BT#>b@Xub
^Qr P.l#pZ
for(int i=0;i<nStartPos.length;i++) 3jn@ [ m
{ %-*vlNC)
if(!fileSplitterFetch.bDownOver) *K98z ?
{ tEEhSG)s%
breakWhile = false; KW;xlJz(j
break; ~::R+Lh(
} fwnpmuJ
} Sx~_p3_5U
if(breakWhile) HOD2/
break; tFSdi.|G=
d,[KcX
9D| FqU |
//count++; R utW{wh
//if(count>4) 5\'%zZ,l
// siteStop(); +Va?wAnr
} g764wl
WR-C_1-pT
I{AU,
System.err.println("文件下载结束！"); BJq}1mn*
} kg61Dgu
catch(Exception e){e.printStackTrace ();} ;`+RSr^8$
} M$?6 '
.J@[v
nn
//获得文件长度 EGDE4n5>I
public long getFileSize() C&st7. (k
{ `MwQ6%lf
int nFileLength = -1; $oQsh|sTI
try{ 6P~"7k
URL url = new URL(siteInfoBean.getSSiteURL()); hHg gH4T
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &59#$LyH`%
httpConnection.setRequestProperty("User-Agent","NetFox"); 5HIpoj;\(
b mm@oi
'?>eW2d
int responseCode=httpConnection.getResponseCode(); 1h#k&r#*3
if(responseCode>=400) qN0#=X
{ Y1'.m5E
processErrorCode(responseCode); I>3]4mI*a
return -2; //-2 represent access is error 8k1r|s@d
} ygW@[^g
#-Rz`Y<&
aK&+p#4t
String sHeader; 0C p}
oU@ljSD
F^NR qE
for(int i=1;;i++) ZYt __N
{ 55cldo
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]6;AK\9TM
//Utility.log(in.readLine()); X@:fW @
sHeader=httpConnection.getHeaderFieldKey(i); /T(\}Z
if(sHeader!=null) ke#;1
{ 4@V]zfu^Q
if(sHeader.equals("Content-Length")) L@_">'pR
{ &+j^{a
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3.0c/v5Go
break; p<zXuocQ
} cGc|n3(
} LJ/qF0L!H
else ^0|NmMJ]
break; 7 h1"8#X
} uBTT {GGQ
} m3(T0.j0P
catch(IOException e){e.printStackTrace ();} -n *>zGc
catch(Exception e){e.printStackTrace ();} 9$,gTU_a
Tb={g;0@
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Utility.log(nFileLength); 9i<-\w^$
_o?(t\B9{
h*KHEg"+
return nFileLength; a-E-hX2
} z;C=d(|nN
.lBY"W&{
|3,V%>z
//保存下载信息（文件指针位置） |3s&Y`x-D
private void write_nPos() iW}l[g8sw!
{ J=X% xb
try{ 4LEE /
output = new DataOutputStream(new FileOutputStream(tmpFile)); NN 6KLbC(
output.writeInt(nStartPos.length); :2pBv#\"qk
for(int i=0;i<nStartPos.length;i++) `,Nn4
{ LZ)m](+M
// output.writeLong(nPos); oe|e+
output.writeLong(fileSplitterFetch.nStartPos); iHn!KV
output.writeLong(fileSplitterFetch.nEndPos); i"]8Zw_D
} 1mJ_I|98
output.close(); DjzUH{6O
} ' f$L
catch(IOException e){e.printStackTrace ();} 7F(F.ut
catch(Exception e){e.printStackTrace ();} S9NN.dKu
} :dguQ|e
b!X"2'
6eT'[Umx
//读取保存的下载信息（文件指针位置） GWInN8.5
private void read_nPos() |NU0tct^
{ qysa!B
try{ #a |ch6B
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); kLVn(dC "
int nCount = input.readInt(); paNw5] -
nStartPos = new long[nCount]; O_Rcd&<mr
nEndPos = new long[nCount]; U[QD!
for(int i=0;i<nStartPos.length;i++) aoDD&JE
{ 7+a%ehwU
nStartPos = input.readLong(); F>QT|
nEndPos = input.readLong(); "Wk{4gS7l
} r^A#[-VyNP
input.close(); `SjD/vNE
} [b.'3a++
catch(IOException e){e.printStackTrace ();} BO4 K#H7
catch(Exception e){e.printStackTrace ();} 9J7J/]7f
} uUz`=4%A
! F <] T
8F^,8kIR
private void processErrorCode(int nErrorCode) RF5q5<0
{ |R;l5ZKvV
System.err.println("Error Code : " + nErrorCode); +F o$o
} em1cc,
%L j0
%x6Ov\s2
//停止文件下载 k9)u3
public void siteStop() i6md fp|k
{ 5Y Q
bStop = true; 1_NG+H]x9
for(int i=0;i<nStartPos.length;i++) Z|(c(H2
fileSplitterFetch.splitterStop(); "Ug/ ',jkV
D*cyFAF
#<wpSs
} S&3X~jD(1
} rj,K`HD
//负责部分文件的抓取 %XI"<Y\yL
**FileSplitterFetch.java Wzqb>.
*/ `(,*IK a
package NetFox; {@V3?pG?p
$% Ci8p
qo6LC>Qg
import java.io.*; 3kiE3*H
import java.net.*; 9Yl8ndP^E
a_{io`h3&
0TO_1 0D
public class FileSplitterFetch extends Thread { eOehgU5x
R6!cK[e]4
5e)6ua,
String sURL; //File URL 2{e dW+
long nStartPos; //File Snippet Start Position 7-d}pgVK
long nEndPos; //File Snippet End Position VyWYfPK
int nThreadID; //Thread's ID ov`^o25f
boolean bDownOver = false; //Downing is over q#99iiG1
boolean bStop = false; //Stop identical JOrELrMx
FileAccessI fileAccessI = null; //File Access interface =_RcoG/^~
N^\2 _T
u m:0y,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException LZr0]g{Pu/
{ G#e9$!
this.sURL = sURL; (!*Xhz,(-
this.nStartPos = nStart; KQ4kZN
this.nEndPos = nEnd; Pr5g6I'G
nThreadID = id; *p&^!ct
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m_m8c8{Y
} :}@C9pqr2
2.LJp}>
#zS1Zf^KP
public void run() Vvm=MBgN
{ QqiJun_m
while(nStartPos < nEndPos && !bStop) nn@^K6
{ 7m:|u*ij2~
o_Jn_3=
v/R[?H)
try{ b0@>xT
URL url = new URL(sURL); .tRr?*V|l
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ot`LZ"H:
httpConnection.setRequestProperty("User-Agent","NetFox"); F qeV3N
String sProperty = "bytes="+nStartPos+"-"; {f+N]Oo*
httpConnection.setRequestProperty("RANGE",sProperty); v2hZq-q
Utility.log(sProperty); *jM_wwG
YDQ:eebg(
gA~20LSt
InputStream input = httpConnection.getInputStream(); K(nS$x1G
//logResponseHead(httpConnection); M{?zvq?d
erx5j\
~;M)qR?]W
byte[] b = new byte[1024]; gjj 93
int nRead; JEWL)
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) d/D,P=j"
{ 0]AN;
nStartPos += fileAccessI.write(b,0,nRead); (C daE!I4Q
//if(nThreadID == 1) 48 W.qzC
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BBHK
} fdlvn*H
D \N \BD
q$r&4s)To
Utility.log("Thread " + nThreadID + " is over!"); sl/=g
bDownOver = true; z Yw;q3"
//nPos = fileAccessI.write (b,0,nRead); t})lr\
} EL^8zyg%%
catch(Exception e){e.printStackTrace ();} ))7LE|1l
} ;LCTCt`
} LHh5 v"zjG
vQ:wW',i
>i "qMZ
//打印回应的头信息 OT%0{2c"]
public void logResponseHead(HttpURLConnection con) C5P$&s\
{ E{tx/$f
for(int i=1;;i++) g;pR^D'M5C
{ jY7=mAd
String header=con.getHeaderFieldKey(i); *YWk1Cwjo
if(header!=null) 00ofHZ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?4XnEDAm
Utility.log(header+" : "+con.getHeaderField(header)); %.mEBI=hs
else W'a(oI
break; V=pMq?Nr
} TG}d3ZU !
} M!1U@6n!=)
j'K38@M:MN
F{<5aLaYti
public void splitterStop() -?s&pKi
{ yuOS&+,P
bStop = true; veeI==]
} WRWWskP
4&QUh+F
Nln`fE/Ht
} 5W/{h q8}}
-LtK8wl^
m9in1RI%
/* pkJ/oT
**FileAccess.java 57wFf-P
*//文件访问(定位，写) <aJ$lseG
package NetFox; ,`k_|//}=
import java.io.*; K]c4"JJ
kb71q:[
O] Y v
public class FileAccessI implements Serializable{ {C3U6kKs;R
ui:=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !/`$AXO
RandomAccessFile oSavedFile; VYZU eh
long nPos; r9# \13-
bLzs?eos
Mi+H#xx16
public FileAccessI() throws IOException 0Vkl`DmeM.
{ e ^Ds
this("",0); 'Gx$Bj
} NYwR2oX
!\FkG8
+oI3I~
public FileAccessI(String sName,long nPos) throws IOException F]UQuOR)
{ %SrM|&[
oSavedFile = new RandomAccessFile(sName,"rw"); j9d!yW
this.nPos = nPos; >I}9LyZt
oSavedFile.seek(nPos); xl(@C*.sC1
} `s|]"'rX
<Mx0\b!
[}OgSP9i
public synchronized int write(byte[] b,int nStart,int nLen) :_ROJ
{ %f j+70
int n = -1; {%C*{,#+8q
try{ LCs__.
oSavedFile.write(b,nStart,nLen); [U>@,BH
n = nLen; .Obn&S
} !M7<BD};
catch(IOException e) K_~h*Yc
{ <[Q3rJ
e.printStackTrace (); Xd<t5{bD!
} S4N(cn&
('O}&F1
D-2.fjo9!
return n; +x=)/;:
} 33'Y[4
"T2"]u<52
eujK4s
} :Zt2'vcGpf
n(1')?"mA
08s_v=cF
/* lx |5?P
**SiteInfoBean.java ,E;;wdIt
*/ )?=YT
package NetFox; ,HB2hHD
|l0Ea
b>\?yL/%+?
public class SiteInfoBean { zce`\ /:
U!(@q!>G
{D`'0Z1"
private String sSiteURL; //Site's URL )w h%|
private String sFilePath; //Saved File's Path |&3x#1A
private String sFileName; //Saved File's Name P`$!@T0=
private int nSplitter; //Count of Splited Downloading File JhHWu<
t23'x0l
^03j8Pc-c
public SiteInfoBean() lDc-W =X=
{//nSplitter的缺省值为5 fB1TFtAh
//default value of nSplitter is 5 KS}hU~
this("","","",5); ^/U27B
} ke_[
`'I{U5;e
]:(W_qEA
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) omSM:f_~
{ "{D6J809
sSiteURL= sURL; aE"[5*a
sFilePath = sPath; G{Yz8]m
sFileName = sName; 3S*AxAeg
this.nSplitter = nSpiltter; y [#pC<^
=<}<Ny
K+*Q@R D
} ;5_{MCPM
m)v''`9LU
"_|oWn
public String getSSiteURL() j.e0;! (L}
{ hR#-u1C
return sSiteURL; F&RgT1*
} L<^j"!0
= ?D(g
tVuWVJ4M
public void setSSiteURL(String value) _"@CGXu
{ ;0rGiWC#
sSiteURL = value; 'e)^m}:?D
} j/`94'Y
k%s_0 @
a"N4~?US
public String getSFilePath() Y;4!i?el
{ ldha|s.*
return sFilePath; r;BT,jiX
} +mj*o(
te|?)j
d^03"t0O]
public void setSFilePath(String value) N`@NiJ(O;
{ N;Dp~(1 J1
sFilePath = value; >F1kR\!
} (jjTK'0[
{7u[1[L1
j#r6b]k(Hv
public String getSFileName() YHNR3
{ `?T#Hl>j
return sFileName; d)f@ 5/<
} Y3.$G1{#0w
Hnknly
r{\1wt
public void setSFileName(String value) >r`b_K
{ dzLQI}89+k
sFileName = value; \B F*m"lz
} 1"Z@Q`}
j/=iMq
CTX9zrY*T
public int getNSplitter() |-sPLU&s%
{ -9N@$+T
return nSplitter; S/|,u`g-
} :B3[:MpL}
j',W 64
k@zy
public void setNSplitter(int nCount) v+p{|X-
{ d->|EJP
nSplitter = nCount; XO#/Fv!
} ;g{qYj_
} !!@A8~H
valtev0<
L,y6^J!
/* {{V8;y
**Utility.java !cKz7?w
*/ =qN2Xg/
package NetFox; rpeJkG@+
SJD@&m%?[
u\&b4=nL
public class Utility { P96pm6H_;
+]=e;LN$0
8.F~k~srA
public Utility() F, U*yj
{ SGb;!T*
J>fQNW!{
+"9hWb5
} g^*<f8 ~d
+)JpUqHa
//线程睡眠 h(WrL
public static void sleep(int nSecond) dJ$"l|$$
{ zdXkR]
try{ $kR N h6
Thread.sleep(nSecond); OL4z%mDZi
} %$%&m1Y
catch(Exception e) {U&.D [{&
{ vJAZ%aW
e.printStackTrace (); <ZU=6Hq
} Gt9&)/#
} /cc\fw1+
o7IxJCL=Q
//日志 hig2
public static void log(String sMsg) *#TUGfwy
{ .<kqJ|SVi
System.err.println(sMsg); KNH1#30 K
} v<Bynd-
ECv)v
l5L.5$N
public static void log(int sMsg) ^vG8#A}]
{ 6e&>rq6C
System.err.println(sMsg); >0Q|nCx
} ~]ZpA-*@Ut
} N !TW!
(O0Urm
R|i/lEq
/* H'Yh2a`!o
**TestMethod.java i2~
*/ 4CGPOc
package NetFox; o|jIM9/
J\e+}{
JN7k2]{
public class TestMethod { N},n `Yl.
@&[T _l
@A)R_p
public TestMethod() /x3/Ubmz~x
{ ///xx/weblogic60b2_win.exe l<M'=-Y
try{ hYawU@R
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Ef<b~E@
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \QmCeB
SiteFileFetch fileFetch = new SiteFileFetch(bean); IIy~[4dW
fileFetch.start(); `^lYw:xA
} S_~z-`;h!
catch(Exception e){e.printStackTrace ();} Nj("|`9"
>E*$ E
Bn>8&w/P
} `a9L%z
eb*#'\~'
~on(3|$
public static void main(String[] args) ayAo^q
{ >}(CEzc8
new TestMethod(); p!s}=wI`
} ! !PYP'e
} #A]-ax?Qc}
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