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)); <[gN4x>'
} DvI^3iG8
for(int i=0;i<nEndPos.length-1;i++) <Z1m9O "sy
{ - t4F
nEndPos = nStartPos[i+1]; 6I]{cm
} }ew)QHd
nEndPos[nEndPos.length-1] = nFileLength; @O6 2}F
} _!vuDv%
} 9j;!4AJ1t
*gwo.s
|9m*?7
//启动子线程 qvh8~[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #x6wM~
for(int i=0;i<nStartPos.length;i++) |D;I>O^"R
{ :9>U+)%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Oeg^%Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), W$D:mw7
nStartPos,nEndPos,i); ZS&+<kGD
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .q 4FGPWz
fileSplitterFetch.start(); (G>g0(;D-
} j->5%y
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (r.y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); -ebyW#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", O+DYh=m*p
nEndPos = " + nFileLength); T!&VT;
// fileSplitterFetch[nPos.length-1].start(); PC,I"l
|mw3v>
oBPm^ob4
//等待子线程结束 >T14 J'\
//int count = 0; y?*Y=,"
//是否结束while循环 '2p,0Bk9i
boolean breakWhile = false; p{0rHu[
"GxQ9=Z
0)vX
while(!bStop) 6D4u?P,
{ -OgC.6
write_nPos(); ?O#"x{Pk
Utility.sleep(500); &x4|!"G
breakWhile = true; 9PR?'X;4
py/#h$eY
N71%l
for(int i=0;i<nStartPos.length;i++) %x^U3"7
{ *M~BN}.
if(!fileSplitterFetch.bDownOver) \VAS<?3
{ 2;SiH]HNS
breakWhile = false; @7?L+.r$9
break; nG| NRp
} %F0.TR!!n
} ge&!GO
if(breakWhile) 7x$VH5jie#
break; Fy^8]u*Fu
_6sSS\
V$MMK
//count++; lxLEYDGFS
//if(count>4) R{Me~L?
// siteStop(); +=L^h9F
} <)oW
thh0~g0/
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System.err.println("文件下载结束！"); [@$t35t~
} 7t% |s!~
catch(Exception e){e.printStackTrace ();} Ch&2{ng
} ?ieC>cr
A9y3B^\*
s";9G^:
//获得文件长度 $r(9'm}W
public long getFileSize() ~Y7:08
{ J}VG4}L
int nFileLength = -1; ]n4G]ybK%
try{ u5P2*
URL url = new URL(siteInfoBean.getSSiteURL()); f5t/=/6>F
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j@jUuYuDgl
httpConnection.setRequestProperty("User-Agent","NetFox"); 0SDyE
@ql S #(
gCI{g.[I!
int responseCode=httpConnection.getResponseCode(); T^nOv2@,
if(responseCode>=400) S),acc(d
{ JHsxaX;c
processErrorCode(responseCode); zW; sr.
return -2; //-2 represent access is error pJ@D}2u(
} '!XVz$C
|)YN"nqg
YGCBDH%6
String sHeader; ff2`4_,|
U;Q?Rh-W
Z2I2 [pA
for(int i=1;;i++) !X<dN..
{ ?Lquf&`vP
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); PCiwQ4~
//Utility.log(in.readLine()); 4Mv]z^
sHeader=httpConnection.getHeaderFieldKey(i); \ UiITP<
if(sHeader!=null) rIAbr5CG
{ qL!pDZk
if(sHeader.equals("Content-Length")) /,^AG2]( f
{ k:`yxxYIh
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /baSAoh/e
break; 67P@YL
} /G!M\teeF
} 39Tlt~Psz
else B5/"2i
break; j:'8yFi_
} 43BqNQ0
} t$ 3/ZTx
catch(IOException e){e.printStackTrace ();} GNI:k{H@"?
catch(Exception e){e.printStackTrace ();} s{T6qJ
@`:z$52
7SJtW`~
Utility.log(nFileLength); h9l 6AnbJ
6{?B`gm7g
C.?~D*Q
return nFileLength; oYrg;]H
} ze#r/j;sw
'"]U+aIg
(Ujry =f
//保存下载信息（文件指针位置） 7) Qq
private void write_nPos() Amj'$G|+hj
{ ;a~ e
try{ t'e5!Ma
output = new DataOutputStream(new FileOutputStream(tmpFile)); wp>L}!
output.writeInt(nStartPos.length); \~I>@SG2W+
for(int i=0;i<nStartPos.length;i++) G57c 8}\4
{ h~u|v[@{J
// output.writeLong(nPos); d&t,^Hj
output.writeLong(fileSplitterFetch.nStartPos); Fz@9 @
output.writeLong(fileSplitterFetch.nEndPos); $3^Cp_p6
} ix_&<?8
output.close(); ~qezr\$2
} CjUYwAy$k
catch(IOException e){e.printStackTrace ();} gH|:=vfYUR
catch(Exception e){e.printStackTrace ();} YaAOP'p
} )EIT>u=
irKM?#h
9qX)FB@'i;
//读取保存的下载信息（文件指针位置） XWq@47FR
private void read_nPos() $'93:9tg
{ F0/!+ho
try{ 3?bTs =
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); N<T@GQwkS
int nCount = input.readInt(); z--Y
nStartPos = new long[nCount]; 4>(rskl_
nEndPos = new long[nCount]; ]q3.^F
for(int i=0;i<nStartPos.length;i++) ^W,~
{ Q4F&#^02y
nStartPos = input.readLong(); Jju^4
nEndPos = input.readLong(); o&#!W(
} E{{Kzr2$
input.close(); ^BhS*
} ^D A<=C-[!
catch(IOException e){e.printStackTrace ();} 5b;~&N4~
catch(Exception e){e.printStackTrace ();} |a>,FZv8e
} yUEvva
nXfdf-
-Rbv#Y
private void processErrorCode(int nErrorCode) 2[g kDZ
{ f}w_]l#[G
System.err.println("Error Code : " + nErrorCode); p|Nh:4iN
} ZP9x3MHe
J1@skj4#\~
!:M+7kmr7t
//停止文件下载 HlraOp+
public void siteStop() yVgHu#?PM
{ p'\zL:3
bStop = true; |Ju d*z
for(int i=0;i<nStartPos.length;i++) \"6?*L|]
fileSplitterFetch.splitterStop(); C!W0L`r
k[{ ~eN:
~ ;ObT=
} lwm 9gka
} Y |9
//负责部分文件的抓取 %`}nP3
**FileSplitterFetch.java U[W &D%'
*/ dK>sHUu
package NetFox; v:]z-zU
S9dXkd
KRb'kW
import java.io.*; q@vqhE4
import java.net.*; jR>`Xz
Y]bS=*q
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public class FileSplitterFetch extends Thread { 5Kw?#
i7%`}t
U;t1 K
String sURL; //File URL %BF,;(P
long nStartPos; //File Snippet Start Position nB6 $*'
long nEndPos; //File Snippet End Position O2"5\@HfE
int nThreadID; //Thread's ID Lwn
boolean bDownOver = false; //Downing is over "D'"uMS`H
boolean bStop = false; //Stop identical 61](a;Di
FileAccessI fileAccessI = null; //File Access interface 8yk4#CZ
"<&) G{
DcN!u6sJ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~]SCf@pRk
{ 63/a 0Yn
this.sURL = sURL; P=R-1V
this.nStartPos = nStart; zJov*^T-C
this.nEndPos = nEnd; !wTrWD!
nThreadID = id; zZ;V9KM>v
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *auT_*
} B[9y<FB+
5&qBG@Hw]
KkCsQ~po
public void run() ehTv@2b
{ D!&]jkUN
while(nStartPos < nEndPos && !bStop) K #}t\
{ /h8100
^0&jy:{
nWA>u J5
try{ w@pJ49
URL url = new URL(sURL); /QT>"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P=l 7m*m
httpConnection.setRequestProperty("User-Agent","NetFox"); *P8CzF^>\&
String sProperty = "bytes="+nStartPos+"-"; X0]{8v%
httpConnection.setRequestProperty("RANGE",sProperty); ~ +h4i'
Utility.log(sProperty); hDXaCift
[9G=x[
8*Ty`G&v
InputStream input = httpConnection.getInputStream(); vIf-TQw
//logResponseHead(httpConnection); [}yPy))A
}46Zfg\T6n
}{)Rnb@ >
byte[] b = new byte[1024]; nDyA][
int nRead; 6j95>}@
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #4<=Ira5
{ !*S,S{T8
nStartPos += fileAccessI.write(b,0,nRead); aW9\h_$
//if(nThreadID == 1) xjD."q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X8):R- J
} 9sI&d
*7b?.{
A]ZQ?-L/
Utility.log("Thread " + nThreadID + " is over!"); LW k/h1
bDownOver = true; %+/Dv
//nPos = fileAccessI.write (b,0,nRead); r+k&W
} 'x5p ?m
catch(Exception e){e.printStackTrace ();} bo1J'pU
} sf/m@425
} TbLU[(m-n
q3C
4U~'Oa@p
//打印回应的头信息 <KfR)7I$0a
public void logResponseHead(HttpURLConnection con) 9WI5\`*"
{ W]XM<# ^^
for(int i=1;;i++) 2_ 1RJ
{ ;e.8EL
String header=con.getHeaderFieldKey(i); p=3t!3
if(header!=null) +*,!q7Gt
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {Qc,Nl [?
Utility.log(header+" : "+con.getHeaderField(header)); xojt s;n
else Uz~B`
break; Kwi+}B!
} UA4c4~$S
} (V1;`sI8
oY0*2~sg
t2Jf+t_B7
public void splitterStop() }ice*3'3
{ /GX>L)
bStop = true; ^4NRmlb
} .)=*Yr M
9yaTDxB>
C#e :_e]
} QUaV;6 4
+~ Hb}0ry
V^4v`}Wgx
/* w]nt_xj
**FileAccess.java Bex;!1
*//文件访问(定位，写) 0U:X[2|)
package NetFox; %|ClYr
import java.io.*; pL!,1D!
v 2p
bRrSd:e
public class FileAccessI implements Serializable{ `JY+3d,Ui
v_Df+
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Z=Cw7E
RandomAccessFile oSavedFile; `Tf}h8*
long nPos; ` &bF@$((
kvuRT`/
m5&Ht (I%n
public FileAccessI() throws IOException X)6G:cD
{ > ;#Y0
this("",0); H-nhq-fut
} S=lCzL;j"
R)ZzRz|/
`"PHhCG+z
public FileAccessI(String sName,long nPos) throws IOException L)&^Pu
{ Z,/^lg c,
oSavedFile = new RandomAccessFile(sName,"rw"); l1|*(%p?X
this.nPos = nPos; ^#C+l
oSavedFile.seek(nPos); |&xaV-b9W
} wN10Drc
4`mf^Kf
uF1 4;
public synchronized int write(byte[] b,int nStart,int nLen) lZ)6d-vK
{ xf/K+
int n = -1; .AOc$Nt
try{ mtkZF{3Jx
oSavedFile.write(b,nStart,nLen); ms;zC/
n = nLen; ]kx<aQ^
} ']fyD3N
catch(IOException e) S.Kcb=;"L
{ j,;f#+O`g
e.printStackTrace (); J%|;
} )/JVp>
8t=O=l\
/4OQx0Xmm
return n; B9y5NX
} FyWf`XTO
("ix!\1K@
gK;dfrU.8Y
} qoH:_o8ClO
{5D%<Te
aMGh$\Pg
/* .a :7|L#a
**SiteInfoBean.java GM9[ 0+u;
*/ SP<Sv8Okj
package NetFox; \m}a%/
SmD#hE[
\)wVO*9*0
public class SiteInfoBean { v;5-1
Q]GS#n
kjp~:Bg_(
private String sSiteURL; //Site's URL 5de1rB|
private String sFilePath; //Saved File's Path =liyd74%`
private String sFileName; //Saved File's Name /m;Bwu
private int nSplitter; //Count of Splited Downloading File A^+kA)8
h*D -Vo
v;G/8>GRy
public SiteInfoBean() u/wX7s
{//nSplitter的缺省值为5 s.rQiD
//default value of nSplitter is 5 1 oKY7i$
this("","","",5); &&52ji<3
} h$$JXf
.sQV0jF{
!`7evV:
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 'YGP42#
{ K3h];F!^
sSiteURL= sURL; lH`c&LL-=!
sFilePath = sPath; "Dk@-Ac
sFileName = sName; ^Ss<<
this.nSplitter = nSpiltter; PPrvVGP
ewN|">WXQ
T"3LO[j+
} bv(+$YR
0%,W5w
FZ<6kk4
public String getSSiteURL() ib 'l:GM
{ 2-qWR<E
return sSiteURL; 42hG}Gt
} *y|w9rp
c)N_"#&
ZVJ6 {DS/
public void setSSiteURL(String value) !BrZTo
{ 9}2/ko
sSiteURL = value; 3AR'Zvn
} g#l!b%$
35AH|U7b
tC$+;_=+F
public String getSFilePath() PBW_9&d
{ 6tP!(
return sFilePath; n} !')r
} /Us+>vg!
-L2 +4
(QqeMG,Y
public void setSFilePath(String value) J0e^v
{ yB*aG
sFilePath = value; s"nntC
} psx_gv,
UHi^7jQ
P|?nx"c
public String getSFileName() qFDy)4H)
{ sA: /!9
return sFileName; i=>`=. ~
} Ekrpg^3qp"
W^ask[46R
o](ORS$~
public void setSFileName(String value) -V@ST9`
{ ^iWGGnGS
sFileName = value; bzZdj6>kX
} @q]!C5
Bs`='w%7
oz:J.<j24Z
public int getNSplitter() d3?gh[$
{ iH]0 YT.E
return nSplitter; +JD^5J,-NJ
} >2}*L"YC
&.z-itiV
*"F*6+}w"
public void setNSplitter(int nCount) h<?I?ZR0$
{ "FGgem%9
nSplitter = nCount; _h=h43'3
} L7(.dO0C
} d@cyQFX
3)&rj 7
i ^N}avO
/* Ly, ];
**Utility.java {O!;cI~
*/ r[kHVT8
package NetFox; Kb5}M/8
C5Fq%y{$.
1ATH$x
public class Utility { e2;=OoBK
l<sWM$ez
\B/( H)Cd*
public Utility() HQ4WunH2Y
{ rvnm*e,
{"|GV~
D,-L!P
} ;tD?a7
EmP2r*"rb
//线程睡眠 P:XX8&#
public static void sleep(int nSecond) [ CU8%%7
{ 1_}k)(n
try{ ih:%U
Thread.sleep(nSecond); j}jU.\*v<
} +'` ^ N
catch(Exception e) ND 8;1+3
{ b_~KtMO
e.printStackTrace (); 'e x/IqbK
} H0.&~!,*
} l$!NEOK
=<=[E:B
//日志 )In;nc
public static void log(String sMsg) G jrN1+9=
{ ?f:\&+.&
System.err.println(sMsg); j=>WWlZ
} e<Oz%
V+*1?5w
kwt;pxp i
public static void log(int sMsg) ?0s&Kz4B
{ SnO,-Rg
System.err.println(sMsg); GCcSI;w
} J/vcP
} EJaO"9 (
Z>@\!$Mc
jJ_6_8#
/* SS,'mv
**TestMethod.java aMJ9U)wnK
*/ @(tuE
package NetFox; <("P5@cExU
3URrK[%x`
6XeqK*r*
public class TestMethod { O}lqY?0*
,}Ic($To
AlgVsE%Va
public TestMethod() VD=F{|^
{ ///xx/weblogic60b2_win.exe n6INI~,
try{ jLul:* L
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); xoE,3Sn
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 4Gy3s|{
SiteFileFetch fileFetch = new SiteFileFetch(bean); hA"z0Fszh
fileFetch.start(); iF+50d
} 1 7hXg"B
catch(Exception e){e.printStackTrace ();} 0L7^Vr)
G{|FV m
jBd9 $`
} :4238J8
8ax3"G
'DH_ihZ
public static void main(String[] args) nZS*"O#L
{ g[xn0rG
new TestMethod(); y {Mh ?H
} $4TawFf"nc
} 2 BwpxV8
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