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)); L$ ON=$q5
} yNN2}\[.
for(int i=0;i<nEndPos.length-1;i++) oNEU?+
{ 6"=e+V@
nEndPos = nStartPos[i+1]; % vP{C
} `/|=eQ")o@
nEndPos[nEndPos.length-1] = nFileLength; bC@b9opD
} |w>DZG!}1-
} {< wq}~
m3|,c[M1
Hv IN'
//启动子线程 p,1RRbyc
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; GdP9Uj)n-
for(int i=0;i<nStartPos.length;i++) @?%"nK
{ i2!{.*.
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \NSwoP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $jntT(V
nStartPos,nEndPos,i); j1d=$'a "
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,~kMkBkl~
fileSplitterFetch.start(); 43VuH
} }=L >u>cP
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), uC}YKT>V7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Cy2X>Tl"<E
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", +5HOT{wj
nEndPos = " + nFileLength); Mz{>vb
// fileSplitterFetch[nPos.length-1].start(); My1E@<
N4}h_mh^'
woR)E0'qx
//等待子线程结束 SBF3\
//int count = 0; J$P]>By5:
//是否结束while循环 NCsUC
boolean breakWhile = false; r%a$u%)oD
;x7SY;0*
![V<vIy
while(!bStop) +0a',`yc
{ p1D-Q7F
write_nPos(); Ri3m438
Utility.sleep(500); Z?@07Y[|K
breakWhile = true; mee-Qq:}
UU !I@
~/Ry=8
for(int i=0;i<nStartPos.length;i++) +tA rH C]
{ 9wwvh'T&NK
if(!fileSplitterFetch.bDownOver) Fd91Y
{ FUOvH85f
breakWhile = false; N0Y!
break; [n^___7
} npe*A
} &=UzF
if(breakWhile) 2n7[Op
break; mR{0*<
k |Lm;g
c8Opc"UE
//count++; {B}0LJIpL
//if(count>4) <0vvlOL5
// siteStop(); 4 IHl'*D[#
} +GGj*sD
\"*l:x-u
iVl"H@m/
System.err.println("文件下载结束！"); K~E]Fkw!;
} !XicX9n
catch(Exception e){e.printStackTrace ();} !hc7i=V?
} XR&*g1
`2Z=Lp
{P3,jY^
//获得文件长度 h'}5"m
public long getFileSize() :G`_IB\
{ yA_d${n
int nFileLength = -1; 0O:TKgb&C.
try{ D"Xm9 (
URL url = new URL(siteInfoBean.getSSiteURL()); R5FjJ>JE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mB,7YZv
httpConnection.setRequestProperty("User-Agent","NetFox"); |~/{lE=I
6`s[PKP.
IW46-;l7
int responseCode=httpConnection.getResponseCode(); k^L (q\D
if(responseCode>=400) MaEh8*
{ Vz,WPm$I
processErrorCode(responseCode); N,O[pTwj
return -2; //-2 represent access is error [J];
} M-Js"cB[
Pf!K()<uJ
w9oiu$7),
String sHeader; byMO&Lb*
Ug"B/UUFd
J>'o,"D
for(int i=1;;i++) HOw][}M_w
{ ;L`'xFo>>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #8RQ7|7b|
//Utility.log(in.readLine()); &@Q3CCDS
sHeader=httpConnection.getHeaderFieldKey(i); 'D-imLV<<
if(sHeader!=null) Nhf!;>
{ UO&S6M]v7
if(sHeader.equals("Content-Length")) uaGg8
{ Ff,M~zn
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); (&B & V
break; b)V[d8IA
} MHbRG_zW
} Rl)/[T
else E*ic9Za8`h
break; 9-@w(kMu
} x?%vqg^r
} tsk}]@W
catch(IOException e){e.printStackTrace ();} RsY<j& f
catch(Exception e){e.printStackTrace ();} AiyjrEa%
<wuP*vI"h
|9Y9pked8
Utility.log(nFileLength); 0Icyi#N
mkWIJH
XI0O^[/n{
return nFileLength; X3"V1@-i4$
} mA4v 4z
Sb`>IlT\#
"<&F=gV
//保存下载信息（文件指针位置） PaZFM
private void write_nPos() Qj=l OhM
{ R_*\?^k|A
try{ hsl8@=_ B
output = new DataOutputStream(new FileOutputStream(tmpFile)); _ 9k^Hd[L$
output.writeInt(nStartPos.length); kgQEg)A]!x
for(int i=0;i<nStartPos.length;i++) \<PW_'6
{ 6^zv:C%
// output.writeLong(nPos); LJiMtqg
output.writeLong(fileSplitterFetch.nStartPos); USbiI%
output.writeLong(fileSplitterFetch.nEndPos); 06ueE\@Sg
} )~5`A*Ku
output.close(); $DMeUA\av
} #e#8I7P
catch(IOException e){e.printStackTrace ();} ;6]+/e7O
catch(Exception e){e.printStackTrace ();} !~ZL
} =tP|sYR]^
)sL:iGU
CEUR-LK0
//读取保存的下载信息（文件指针位置） W w8[d
private void read_nPos() 7Ua Ll
{ & .#0jb1r
try{ a@ lK+t
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2`lit@u&u
int nCount = input.readInt(); hA"N&v~
nStartPos = new long[nCount]; tVe*J@i\$
nEndPos = new long[nCount]; ,:#prT[P"
for(int i=0;i<nStartPos.length;i++) K.cNx
{ sz)3 z
nStartPos = input.readLong(); F;z FKvn
nEndPos = input.readLong(); D~1nh%x_
} fb#Ob0H
input.close(); { ~Cqb7
} jem$R/4"
catch(IOException e){e.printStackTrace ();} |S4yol
catch(Exception e){e.printStackTrace ();} 3v{GP>
} O,bj_CWx
5!5P\o
s=6w-'; V
private void processErrorCode(int nErrorCode) }^QY<Cp|
{ W=|B3}C?
System.err.println("Error Code : " + nErrorCode); pa+y(!G
} 6 o+zhi;E
P#yS]F/
G U!XD!!&
//停止文件下载 eAl&[_o|S
public void siteStop() #fFEo)YG
{ LAr6J
bStop = true; YY.;J3C
for(int i=0;i<nStartPos.length;i++) #v`G4d
fileSplitterFetch.splitterStop(); ;bZ)q
J|I|3h<T
S'A~9+
} v5*SoUOF
} 1.';:/~(
//负责部分文件的抓取 ckTnb
**FileSplitterFetch.java u?aq' "t
*/ B0YY7od
package NetFox; OixQlAb{
Ck[Z(=b$$:
C4n5U^
import java.io.*; !|`YNsR
import java.net.*; =GLsoc-b
@P~u k
S>'wb{jj!
public class FileSplitterFetch extends Thread { >#V8l@IH
LN7;Yr
rL%xl,cn<
String sURL; //File URL (K2 p3M^
long nStartPos; //File Snippet Start Position #!5GGe{I
long nEndPos; //File Snippet End Position ."h;H^5
int nThreadID; //Thread's ID B[Tw0rQ
boolean bDownOver = false; //Downing is over mMa7Eyaf
boolean bStop = false; //Stop identical CjO/q)vV
FileAccessI fileAccessI = null; //File Access interface #4|?;C)u\
=|jOio=s:
v=/V<3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |g7E*1Ie
{ H%/$Rqg
this.sURL = sURL; ^%_LA't'R
this.nStartPos = nStart; >`lf1x
this.nEndPos = nEnd; L ~
nThreadID = id; kp0>8rkF
fileAccessI = new FileAccessI(sName,nStartPos);//定位 O'p7^"M
} +C+3DwN
zL>nDnL 4
7gJ`G@y
public void run() l\(t~Q
{ 'T.> oP0>
while(nStartPos < nEndPos && !bStop) 1~_]"Y'
{ z~X]v["d
$y`|zK|G-
#_H=pNWe
try{ nhy3E
URL url = new URL(sURL); 6%5A&&O(b
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @5kN L~2
httpConnection.setRequestProperty("User-Agent","NetFox"); 9,F(f}(t
String sProperty = "bytes="+nStartPos+"-"; .2u%;)S
httpConnection.setRequestProperty("RANGE",sProperty); qg'm<[
Utility.log(sProperty); N($j;<Q
qC]D9 A
%u!#f<"[
InputStream input = httpConnection.getInputStream(); OtnYv
//logResponseHead(httpConnection); ]P 2M
yhTe*I=Gk
uT=sDWD:
byte[] b = new byte[1024]; 2Yyc`o0R;h
int nRead; W<58TCd
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) NW~n+uk5v
{ dz7*a{
nStartPos += fileAccessI.write(b,0,nRead); ]5} =r
//if(nThreadID == 1) ZM5[ o m
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7IFUsli]
} &\5T`|~)!
=JEnK_@?K\
6C
Utility.log("Thread " + nThreadID + " is over!"); 3L#KHTM
bDownOver = true; RJGf@am&
//nPos = fileAccessI.write (b,0,nRead); n RXf\*"3
} (3_2h4O
catch(Exception e){e.printStackTrace ();} E]+W^VG
} Ot(EDa9}IJ
} o{:D
,g/UPK8K=
ku\_M
//打印回应的头信息 4cs`R+]o
public void logResponseHead(HttpURLConnection con) ;B tRDKn
{ *X,vu2(I-=
for(int i=1;;i++) fOrqY,P'
{ n /rQ*hr
String header=con.getHeaderFieldKey(i); mWO=(}Fb\
if(header!=null) w8>p[F5`O
//responseHeaders.put(header,httpConnection.getHeaderField(header)); X, J.!:4`
Utility.log(header+" : "+con.getHeaderField(header)); [5:F
else CjIkRa@!x
break; Prr<:q
} a-O9[?G/x
} \ar.(J
koaH31Q
ZfMJU
public void splitterStop() XD*$$`+#
{ B9+oI cO
bStop = true; P 0,]Ud
} 9B<y w.
RJ@d_~%U
DGp'Xx_8
} 7+?
A*@!tz<
lK}F>6^\
/* eZf-i1lJ
**FileAccess.java ^@jOS{f l
*//文件访问(定位，写) Oq|pd7fcgm
package NetFox; )D(XDN
import java.io.*; AEEy49e
KJSN)yn\
e}aD<EG
public class FileAccessI implements Serializable{ QK//bV)
R0{n0Br
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Nnx"b 5I}n
RandomAccessFile oSavedFile; TN` pai0
long nPos; jtl7t59R
lHZf'P_Wx
o#E z_D[
public FileAccessI() throws IOException -rU *)0PR
{ v%B^\S3)
this("",0); e8P |eK
} ~D 5'O^
_RhCVoeB
u9'4q<>&
public FileAccessI(String sName,long nPos) throws IOException |9}G
{ Z@j0J[s
oSavedFile = new RandomAccessFile(sName,"rw"); :0#!=
this.nPos = nPos; pH)V:BmJ
oSavedFile.seek(nPos); 8`'_ckIgr
} RYmk6w!w
1G$kO90
B*,9{g0m/
public synchronized int write(byte[] b,int nStart,int nLen) /ptIxe
{ i7*4hYY
int n = -1; ^D/*Hp _
try{ 5GC{)#4
oSavedFile.write(b,nStart,nLen); YAd.i@^
n = nLen; <A+Yo3|7
} @lBR;B"
catch(IOException e) ~9 K4]5K-
{ 7nfQ=?XNK
e.printStackTrace (); =7#)8p[
} v-&^G3
2I6c7H s
BQt!L1))
return n; TQYud'u/
} Rl<~:,D
~(G]-__B<
F|Jo|02
} A*E$_N
g9p#v$V
\tU91VIj
/* 1+Ja4`o,iS
**SiteInfoBean.java 0=7C-A1(D
*/ Xg#Dbf4
package NetFox; e6#^4Y/+`
Ewu 7tq Z
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public class SiteInfoBean { -KbT[]
Cv~t~
Ca]vK'(
private String sSiteURL; //Site's URL 9A)(K,
private String sFilePath; //Saved File's Path =as]>?<
private String sFileName; //Saved File's Name rVFAwbR
private int nSplitter; //Count of Splited Downloading File "5ah{,
e-\J!E'1F
,,b_x@y*
public SiteInfoBean() 980[]&(
{//nSplitter的缺省值为5 $UO7AHk
//default value of nSplitter is 5 - C8h$P
this("","","",5); v"=^?5B
} lbTz
q'd6\G0}
"k5 C?~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 's!EAqCN
{ ]D%D:>9|/
sSiteURL= sURL; <-X)<k
sFilePath = sPath; u!X[xe;
sFileName = sName; ]%F3 xzOk
this.nSplitter = nSpiltter; |OuZaCJG
qvhTc6oH
.kvuI6H
} w%j 6zsTz
FpCj$y~3
vQYd!DSh
public String getSSiteURL() Xy=|qu
{ rsy'ZVLUj
return sSiteURL; n"d~UV^Uw
} >"N\ZC^
4|7L26,]5
N{ ;{<C9Z
public void setSSiteURL(String value) =`Nnd@3v
{ <fWho%eOK
sSiteURL = value; {Km|SG[-q
} 5|wQeosXxI
hjaI&?w
q1`uS^3`
public String getSFilePath() %\%1EZQ%
{ <iv9Mg}
return sFilePath; $l-j(=Md
} Oa CkU
J1yy6Wq3[
1 NLawi6
public void setSFilePath(String value) 5{[3I|m{
{ IcI y
sFilePath = value; !W{|7Es?.
} |4x&f!%m
c[@>#7p`o
j+PW9>Uh
public String getSFileName() `:?padZG
{ fh:=ja?bM3
return sFileName; X NnsMl
} **dGK_^T0
mWta B>f
hFs0qPVY
public void setSFileName(String value) DV]Kd 7
{ &%C4rAd2
sFileName = value; _nOio?
} !fyE Hk
~)Ny8Dh
OCY7Bls4
public int getNSplitter() 2gb49y~
{ ZLxe$.V_
return nSplitter; 5H""_uw
} C7eaioW$
0 l G\QT
j#<#o:If
public void setNSplitter(int nCount) DZ(e^vq
{ X}h{xl
nSplitter = nCount; [&3G `8hY
} f+1)Ju~
} #^%Rk'W
/,$6`V
,K8PumM_
/* Bn}@wO
**Utility.java RkP7}ZA;
*/ ^V_vpr]}P
package NetFox; z2wR]G5!
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BY32)8SH
public class Utility { ]e7D""
+SZ#s:#SE
~$YFfv>
public Utility() gXc&uR0S
{ xBR2tDi%
v=iz*2+X
O#CxS/M5
} w9H%u0V?
3Akb|r
//线程睡眠 '?wv::t
public static void sleep(int nSecond) 2gg5:9
{ -QI1>7sl
try{ ^L*:0P~
Thread.sleep(nSecond); kG@1jMPtQ
} !@%m3)T8
catch(Exception e) e J2wK3R
{ )TVyRYZ1
e.printStackTrace (); .#lQZo6$\|
} \/S?.P#L~
} }7wQFKME
c3g\*)Jz"F
//日志 X;6&:%ZL@^
public static void log(String sMsg) g>T'R Vb
{ [[LCEw
System.err.println(sMsg); xH; 4lw
} MpGWt#
v|CRiwx
J:M^oA'N:>
public static void log(int sMsg) P_lk40X
{ f:=q=i
System.err.println(sMsg); }V6}>!Sb
} &HT PeB
} |JnJ=@-y
6 @'v6 1'
vAHJP$x
/* |A[Le ;,
**TestMethod.java Go+f0aig
*/ enDjP
package NetFox; | t3_E
"&77`R
;,'eO i
public class TestMethod { $l0^2o=
haqL DVrf
lHT?
public TestMethod() li$(oA2
{ ///xx/weblogic60b2_win.exe zl4Iq+5~6Q
try{ ]geO%m
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =cX&H
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); oju4.1
SiteFileFetch fileFetch = new SiteFileFetch(bean); P0 hC4Sxf
fileFetch.start(); GyRU/0'BME
} "qMd%RP
catch(Exception e){e.printStackTrace ();} Y GvtG U-
}+,1G!?z
)LKutN?tBy
} Y{f;qbEQH'
$ [0
mst-:F[h
public static void main(String[] args) 2PAotD4+I
{ C[|jJ9VE,
new TestMethod(); 6psK2d0
} }gGcYRT
} "N D1$l
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