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)); {e 14[0U-
} YuO.yh_
for(int i=0;i<nEndPos.length-1;i++) tS6qWtE
{ vw9@v`k
nEndPos = nStartPos[i+1]; M!o##* *`
} a^I\ /&aw'
nEndPos[nEndPos.length-1] = nFileLength; LcTP#
} #"G]ke1l$
} lgk.CC
{N+$Q'
GB=X5<;
//启动子线程 #AJM6* G9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $|@ (
for(int i=0;i<nStartPos.length;i++) gDpVeBd[
{ 1ukTA@Rj&
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), EFM5,gB.m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Iy&!<r7:]0
nStartPos,nEndPos,i); , K~}\CR
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZQV6xoN;r
fileSplitterFetch.start(); Jcd-
} J| w>a
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), VZKvaxIk6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); gi1^3R[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .[ICx
nEndPos = " + nFileLength); RMdk:YvBg
// fileSplitterFetch[nPos.length-1].start(); Hquc o
`r9!zffyS
m+]K;}.}R
//等待子线程结束 X aMJDa|M
//int count = 0; e w$B)W
//是否结束while循环 g,!L$,/F
boolean breakWhile = false; ?Lk)gO^C
\"P%`C
V2wb%;q
while(!bStop) sBT2j~jhJ
{ s Z].8.
write_nPos(); r7%I n^k
Utility.sleep(500); "ut39si
breakWhile = true; z7fp#>uw
I 7{T
#Lh;CSS
for(int i=0;i<nStartPos.length;i++) *XIF)Q=<>
{ kaVxT_
if(!fileSplitterFetch.bDownOver) ivJ@=pd)B
{ |v3T!
breakWhile = false; ;,%fE2c
break; gCB |DY
} @niHl
} Swig;`
if(breakWhile) B|C2lu
break; G3Hx!YW
Ng2twfSl$
\@c,3
//count++; 52Z2]T c,
//if(count>4) LTQ"8
// siteStop(); &]|?o_p3W
} iu=7O
:(P9mt
8e1UmM[
System.err.println("文件下载结束！"); 3YOq2pW72G
} "*e$aTZB\
catch(Exception e){e.printStackTrace ();} qN9(S:_Px
} -=)H{
KQ% GIz x
DEKP5?]
//获得文件长度 Z>k#n'm^z
public long getFileSize() "o-zy'I
{ $r@zs'N
int nFileLength = -1; 6]WAUK%h
try{ 98IJu
URL url = new URL(siteInfoBean.getSSiteURL()); -b9\=U[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R'as0 u\
httpConnection.setRequestProperty("User-Agent","NetFox"); SJn;{X>)q
[}E='m}u9+
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int responseCode=httpConnection.getResponseCode(); On9A U:\
if(responseCode>=400) @k,#L`3^
{ P~>OS5^
processErrorCode(responseCode); "c%0P"u
return -2; //-2 represent access is error =(j1rW!
} |6sp/38#p
d;Ym=YHJtn
:^6y7&o[
String sHeader; *K8$eDNZ
U)]oO
/K@XzwM
for(int i=1;;i++) ;PF<y9M
{ &R'c.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); aFX=C>M
//Utility.log(in.readLine()); !C':
sHeader=httpConnection.getHeaderFieldKey(i); uP)'FI
if(sHeader!=null) _^Ubs>d=*
{ /L g)i\R;
if(sHeader.equals("Content-Length")) g[' ^L+hd
{ 8Z8gRcv{p
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2j[=\K]
break; C!<Ou6}!b
} XPXIg
} )4e.k$X^
else vtg!8u4
break; x}Eg.S
} {T$9?`h~M
} Cgk<pky1
catch(IOException e){e.printStackTrace ();} y@S$^jk.
catch(Exception e){e.printStackTrace ();} U`(ee*}o
k_#ak%m/
t%0VJB,Q2
Utility.log(nFileLength); yW=::=
y&$A+peJ1
NZ:,ph
return nFileLength; Y.(PiuG$G
} %v M-mbX
Ju@c~Xm
{BN#h[#B{
//保存下载信息（文件指针位置） t\dN DS
private void write_nPos() :D5Rlfj
{ L\J;J%fz.
try{ ,f%S'(>w
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~g]Vw4pv
output.writeInt(nStartPos.length); I3L<[-ZE
for(int i=0;i<nStartPos.length;i++) zj{pJOM06
{ gD@){Ip
// output.writeLong(nPos); lgL%u K)
output.writeLong(fileSplitterFetch.nStartPos); {UI+$/v#
output.writeLong(fileSplitterFetch.nEndPos); N)X3XTY
} IVY]EkEG~
output.close(); Woym/[i
} reu*53r]
catch(IOException e){e.printStackTrace ();} Q~ w|#
catch(Exception e){e.printStackTrace ();} 0 1rK8jX
} W' VslZG
tCH!my_
L ca}J&x]^
//读取保存的下载信息（文件指针位置） v0{i0%d,?
private void read_nPos() W:2( .?
{ $t[FH&c(
try{ 9s q
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Tx# Mn~xD
int nCount = input.readInt(); N#_H6TfMG
nStartPos = new long[nCount]; L,/%f<wd
nEndPos = new long[nCount]; .W%)*&WH\
for(int i=0;i<nStartPos.length;i++) b{&)6M)zo
{ M'O <h
nStartPos = input.readLong(); ?dg[:1R}
nEndPos = input.readLong(); Se}c[|8
} j3V -LnA
input.close(); 194)QeoFw
} ydA8wL
catch(IOException e){e.printStackTrace ();} TF\C@4Z
catch(Exception e){e.printStackTrace ();} S9y}
} b2Fe<~S{
K($Npuu]
6<QQ@5_
private void processErrorCode(int nErrorCode) @Cyvf5|bL
{ FDs>m #e
System.err.println("Error Code : " + nErrorCode); QZ
} *L^,|
n b?lTX~
.|70;
//停止文件下载 |0b`fOS
public void siteStop() i[3'ec3
{ [}=B8#Jl-C
bStop = true; ![=yi tB
for(int i=0;i<nStartPos.length;i++) f}P3O3Yv&
fileSplitterFetch.splitterStop(); 6A-|[(NS
904}Jh,
G5 WVr$
} |u<7?)mp
} wlqksG[B
//负责部分文件的抓取 ^6V[=!& H
**FileSplitterFetch.java yNBfUj -L
*/ &j"?\f?
package NetFox; db7B^|Di
g8% &RG
#q=Efn'
import java.io.*; 583|blL
import java.net.*; '-~~-}= sJ
1>h]{%I
u&7[n_
public class FileSplitterFetch extends Thread { zRr*7G
#)O65GI
aX'*pK/-
String sURL; //File URL _Y;W0Z
long nStartPos; //File Snippet Start Position %P|/A+Mg"
long nEndPos; //File Snippet End Position 3F2w-+L
int nThreadID; //Thread's ID ?CPahU
boolean bDownOver = false; //Downing is over bq*eH (qx
boolean bStop = false; //Stop identical \_f(M|
FileAccessI fileAccessI = null; //File Access interface on`3&0,.
<>rneHl8
m;QMQeGz
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException hz@bW2S.
{ E ~<JC"]
this.sURL = sURL; rjYJs*#
this.nStartPos = nStart; G_,jgg7
this.nEndPos = nEnd; >|UOz&
nThreadID = id; %IWPM"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2FJ*f/
} ^<2p~h0 \
LZY"3Jn[nQ
lt8|9"9<
public void run() A3/k@S-R2
{ 1mG-}
while(nStartPos < nEndPos && !bStop) kt:! 7
{ vl:KF7:#m
@\#td5'
tGa8W
try{ Gyc]?m
URL url = new URL(sURL); u'BaKWPS
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (*iHf"=\
httpConnection.setRequestProperty("User-Agent","NetFox"); [{,1=AB
String sProperty = "bytes="+nStartPos+"-"; SO!8Di
httpConnection.setRequestProperty("RANGE",sProperty); VMWf>ZU
Utility.log(sProperty); 0@oJFJrO
2JBR)P
4,DeHJjAlE
InputStream input = httpConnection.getInputStream(); t b}V5VH
//logResponseHead(httpConnection); /k3:']G,s
oCz/HQoBk
/7YIn3
byte[] b = new byte[1024]; <RL]
int nRead; <)D$51 &0
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9\7en%(M
{ zTU0HR3A
nStartPos += fileAccessI.write(b,0,nRead); 'D1xh~
//if(nThreadID == 1) /j.9$H'y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;:NJCuG
} +6+i!Sip
eJ-nKkg~a
E7hY8#G
Utility.log("Thread " + nThreadID + " is over!"); 4o[{>gW
bDownOver = true; sfl<qD+?
//nPos = fileAccessI.write (b,0,nRead); \'O"~W
} )Pv%#P-<
catch(Exception e){e.printStackTrace ();} IH+|}z4N?>
} UkFC~17P
} Z,PPu&lmE/
Qo|\-y-#
tKXIk9e
//打印回应的头信息 *s3/!K
public void logResponseHead(HttpURLConnection con) 7@W>E;go
{ X"eYK/7
for(int i=1;;i++) vnuN6M{
{ Ig{0Z">
String header=con.getHeaderFieldKey(i); f3y=Wxk[
if(header!=null) c-sfg>0^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); El8,,E
Utility.log(header+" : "+con.getHeaderField(header)); |2A:eI8 ^
else SOIN']L|V[
break; do'GlU oMC
} 'LDQgC*%
} \s\?l(ooq"
wUJcmM;
r5^eNg k
public void splitterStop() k+*u/neh
{ x]j W<A
bStop = true; %8v\FS
} 1< ?4\?j
x kD6Iw
MF'JeM;H
} 6ik$B
o)/ 0a
"#g}ve,
/* iWR)ke
**FileAccess.java <F'\lA9
*//文件访问(定位，写) ~wdGd+ez
package NetFox; cU
import java.io.*; {_*yGK48n
)t%b838l%
Dw"\/p:-3
public class FileAccessI implements Serializable{ 7zj{wp!
nO-#Q=H,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 h{qgEIk&
RandomAccessFile oSavedFile; 8eRLy/`gd
long nPos; #<xm.
6aj!Q*(WT
\{NO?%s0p
public FileAccessI() throws IOException VIbq:U
{ E{vbO/|kf
this("",0); 3OB"#Ap8<
} &7s.`
4skD(au8
yf,z$CR
public FileAccessI(String sName,long nPos) throws IOException qxc[M8s
{ x?<FJ"8"k
oSavedFile = new RandomAccessFile(sName,"rw"); % ]U
this.nPos = nPos; vP,n(reM
oSavedFile.seek(nPos); 7xR\kL.,
} _#8MkW#]~
"J1 4C9u
!<F3d`a
public synchronized int write(byte[] b,int nStart,int nLen) ?V=CB,^
{ 6L~n.5B~o
int n = -1; E?@m?@*/
try{ CvdN"k
oSavedFile.write(b,nStart,nLen); : rVnc =k
n = nLen; cz$2R
} T u'{&
catch(IOException e) :23P!^Y
{ !5N.B|Nt
e.printStackTrace (); 5lum$5
} |':{lH6+1
Y4YJJYvD
.RL=xb|[
return n; {4PwLCy
} GA.8@3
z(~_AN M4,
u1.BN>G
} ~>XxGjxe
eJX#@`K
ji="DYtL
/* R@2X3s:
**SiteInfoBean.java A=>u 1h69
*/ D m9sL!
package NetFox; Xwtqi@zlE
h yIV.W/
[-x7_=E#
public class SiteInfoBean { k;W XB|k
5-A\9UC*@
_VXN#@y
private String sSiteURL; //Site's URL }GIt!PG
private String sFilePath; //Saved File's Path Yr|4Fl~U
private String sFileName; //Saved File's Name !Z6{9sKR=]
private int nSplitter; //Count of Splited Downloading File o !7va"
<oeIcN7d
v-Sd*(6
public SiteInfoBean() ,"ql5Q4
{//nSplitter的缺省值为5 cc34e
//default value of nSplitter is 5 *lb<$E]="!
this("","","",5); >-c8q]()ly
} K,UMqAmk
.G\7cZ
fXB0j;A
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `F6C-
{ ?@8[e9lLD
sSiteURL= sURL; :v 4]D4\o
sFilePath = sPath; IRbfNq^:
sFileName = sName; FgO)DQm
this.nSplitter = nSpiltter; _vZOZKS+
IGN1gs
B/C,.?Or
} -F>jIgeC2v
I}Q2Vu<
T9&1VW
public String getSSiteURL() wQLSf{2
{ DTs;{c
return sSiteURL; h`wD
} BerwI 7!=
K|@G t%Y
2Rz
public void setSSiteURL(String value) QSj]ZA
{ L%5%T;0'~
sSiteURL = value; \j.:3Xr
} @ .KGfNu
FPTK`Gd0
h7@6T+#WoT
public String getSFilePath() A)~6Im
{ B-ESFATc
return sFilePath; "w_aM7x_
} i?;Kq~,
'f|o{
L rPkxmR
public void setSFilePath(String value) y?!"6t7&
{ ET >](l9
sFilePath = value; uIrG*K
} |&jXp%4T
w=@Dv
YoE3<[KD(
public String getSFileName() JN6B~ZNf
{ 'm9` 12H
return sFileName; uVU)d1N
} zn(PI3+]!
Ct|A:/z(
A70d\i
public void setSFileName(String value) 'H!XUtFs"
{ FgI3
sFileName = value; l+0P
} ?hM64jI|
y3ikWnx
59-c<I/}f
public int getNSplitter() ,2)6s\]/b
{ lys#G:H]
return nSplitter; &~w}_Fjk
} }&3~|kP~O
q,6DEz
P }uOJVQ_
public void setNSplitter(int nCount) -%dCw6aX+
{ {_dvx*M
nSplitter = nCount; %K QQ,{ b
} d5l UGRg
} QdC<Sk!G
a}uSm/S
w*MpX U<
/* Ca3~/KrM
**Utility.java t0I{q0
*/ =rK+eG#,
package NetFox; >OK^D+v"j
8.~kK<)!
yOKI*.}
public class Utility { {}x^ri~
]+$?u&0?w
[trwBZ^D~
public Utility() bJ;'`sw1
{ ;UP$yM;
UY2OZ&&
2Hv+W-6v
} yiI1x*^
>"<Wjr8W!$
//线程睡眠 !g.?
public static void sleep(int nSecond) qjc4.,/
{ RX5dO%
try{ 8KNZ](Dj
Thread.sleep(nSecond); r"R#@V\'1b
} OUXR
catch(Exception e) rXU\
{ DFTyMB1H
e.printStackTrace (); \^%}M!tan
} <d_!mKw
} @OHm#`~
:/Qq@]O>
//日志 4a]P7fx-
public static void log(String sMsg) ]g&TKm
{ PiYxk+N
System.err.println(sMsg); })?GzblI&
} pHJ3nHLQ
vZoaT|3 G]
-D$8
public static void log(int sMsg) "w.3Q96r
{ xZv#Es%#
System.err.println(sMsg); YUIi;
} ?S$P9^ii'
} "FKOaQ%IH
W{gb:^;zb
:4%k9BGAj"
/* # 4PVVu<
**TestMethod.java ^ovR7+V
*/ {> 0wiH#!E
package NetFox; Z/;aT -N
Vy,DN~ag
5o8EC" 0
public class TestMethod { {,~3.5u
}~e%J(
/Mu@,)''
public TestMethod() Hg$lXtn]
{ ///xx/weblogic60b2_win.exe 46&/gehr
try{ 4Wm@W E
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); P}7'm M
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 'y3!fN=h
SiteFileFetch fileFetch = new SiteFileFetch(bean); :A'y+MnK<
fileFetch.start(); %n:k#
} .UY^oR=b{
catch(Exception e){e.printStackTrace ();} 8eHyL
3x'|]Ns
O+Y6N
} k{SAvKx=
wT8DSq
HqT#$}rv
public static void main(String[] args) @'!SN\?W8
{ JB[~;nLlC
new TestMethod(); zv,jM0-
} oHn Ky[1
} #KexvP&*
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