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)); H}hiT/+$
} `)T13Xv
for(int i=0;i<nEndPos.length-1;i++) KbA?7^zo`
{ Utnr5^].2O
nEndPos = nStartPos[i+1]; WE:24b6
} d?A 0MKnl
nEndPos[nEndPos.length-1] = nFileLength; YoBDvV":@
} *%%g{ 3$
} VHIOwzC
w5Y04J
7/I,HxXp!
//启动子线程 3h$6t7=C
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; < HVl(O
for(int i=0;i<nStartPos.length;i++) ]~'5\58sP
{ E87Ww,z8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), tMf}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3=aQG'B
nStartPos,nEndPos,i); MygfT[_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); l1BtI_7p
fileSplitterFetch.start(); {>hC~L?6
} W3MJr&p
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fSK]|"c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,(EO'T[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `p2+&&]S
nEndPos = " + nFileLength); Rh_np
// fileSplitterFetch[nPos.length-1].start(); O$_)G\\\m
|)(VsVG&
E&2OD [iX
//等待子线程结束 S4Y&
//int count = 0; u)}$~E>
//是否结束while循环 UC]\yUK1J
boolean breakWhile = false; =8AO:
K,+LG7ec
~A'!2
while(!bStop) }`%*W`9b
{ J&W)(Cf
write_nPos(); 3@dL/x4A
Utility.sleep(500); c;Pe/d
breakWhile = true; 7z JRJ*NB
Yc_8r+;(
p<2L.\6"
for(int i=0;i<nStartPos.length;i++) 2^h27A
{ 6dabU*
if(!fileSplitterFetch.bDownOver) J8uLJ
{ v+46QK|I&
breakWhile = false; /:~\5}tW
break; tn(JC%?^
} ,)Me
} s4A43i'g!h
if(breakWhile) *>7>g"
break; m% -g~q
j*so9M6|c
HN=V"a
//count++; Pg,b-W?n*
//if(count>4) dJJP3}M/
// siteStop(); G_bG
} &"f";
n}F&1Z
JTO~9>$ B
System.err.println("文件下载结束！"); de.&`lPRf
} Dz>^IMsY
catch(Exception e){e.printStackTrace ();} %b&".mN
} p>RNPrT
Ta ?_5
x$5) ^ud?
//获得文件长度 UO0{):w>
public long getFileSize() iU$] {c2;A
{ \?[v{WP)
int nFileLength = -1; LClNxm2X
try{ cv998*|X:
URL url = new URL(siteInfoBean.getSSiteURL()); Ktb\ bw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); xST8|H
httpConnection.setRequestProperty("User-Agent","NetFox"); 5D\f8L
JjPKR?[>
PF)jdcX
int responseCode=httpConnection.getResponseCode(); K1mPr^3rC
if(responseCode>=400) `^u>9v-+'
{ *6sl
processErrorCode(responseCode); K2M~-S3
return -2; //-2 represent access is error Cn'(<bl
} *SU\ABcov
G18F&c~
sqEI4~514
String sHeader; $?Yry.2
^U `[(kz=
Ixb=L(V
for(int i=1;;i++) 2|3)S`WZl
{ :o0JY= 5
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;&<{ey
//Utility.log(in.readLine()); "?]{%-u
sHeader=httpConnection.getHeaderFieldKey(i); LJd5;so-
if(sHeader!=null) diJLZikk
{ c`J.Tm[_u
if(sHeader.equals("Content-Length")) QLXN*c
{ 4 !i$4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); wQqb`l7+
break; .{ocV#{s
} jF ^~p9z
} kpJ@M%46
else UtPLIal
break; F_w Z"e6
} x2OaPlG,&V
} {P*pkc
catch(IOException e){e.printStackTrace ();} \|H!~)h$1
catch(Exception e){e.printStackTrace ();} %eX{WgH
E@@5BEB ~
'Y*E<6:
Utility.log(nFileLength); ',Y.v"']4
'8Q]C*Z
xbdN0MAU
return nFileLength; rM`X?>iT+
} ![`Ay4AZ@a
vI:;A/&
jr)1(**
//保存下载信息（文件指针位置） 'FqQzx"r
private void write_nPos() Huy5-[)15
{ .<jr0,i
try{ YPU*@l>
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5:pM4J
output.writeInt(nStartPos.length); QKyo`g7
for(int i=0;i<nStartPos.length;i++) p`b"-[93
{ 61SlVec*o8
// output.writeLong(nPos); o|>'h$
output.writeLong(fileSplitterFetch.nStartPos); -e_hrCW&9
output.writeLong(fileSplitterFetch.nEndPos); 3kw,(-'1
} f[@77m*
output.close(); s3~lT.
} &M46&^Jho
catch(IOException e){e.printStackTrace ();} pOGeruu?
catch(Exception e){e.printStackTrace ();} v=0(~<7B
} GR&z,
6g|*`x{
d ^^bke$~
//读取保存的下载信息（文件指针位置） C`$n[kCJ
private void read_nPos() l n{e1':$"
{ 8K.R=
try{ Id_2PkIN$~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); r"C
int nCount = input.readInt(); SQ44
nStartPos = new long[nCount]; YM1'L\^
nEndPos = new long[nCount]; TT2d81I3m
for(int i=0;i<nStartPos.length;i++) "3Uv]F
{ !Fca~31R'
nStartPos = input.readLong(); M$y+q ^
nEndPos = input.readLong(); A#Iyb){Y
} [BWNRC1
input.close(); -wp|RD,}(
} Cbg!:Cws
catch(IOException e){e.printStackTrace ();} FKIw!m ~
catch(Exception e){e.printStackTrace ();} ZIf
} 5*j?E
/I1h2E
3jGWkby0
private void processErrorCode(int nErrorCode) Y'1S`.
{ gbI^2=YT'
System.err.println("Error Code : " + nErrorCode); mkYqpD7
} Sm)Ha:[4
hWM< 0=
]"t@-PFX<
//停止文件下载 x}_]A$nV
public void siteStop() Zo|.1pN
{ z>XrU>}
bStop = true; =T-&j60
for(int i=0;i<nStartPos.length;i++) |uX,5Q#6
fileSplitterFetch.splitterStop(); lt ^GvWg
FoNSM$x
[h^2Y&Au5
} M^O2\G#B
} 8VeQ-#7M/
//负责部分文件的抓取 isQ[ Gc!8
**FileSplitterFetch.java v/](yT
*/ [Yo,*,y31
package NetFox; brW :C?}
d@ i}-;
?\vh9
import java.io.*; N9jH\0nG
import java.net.*; Hw7;;HK 7
7Nk!1s:
}RzWJ@QD<
public class FileSplitterFetch extends Thread { '_GrD>P)-
xfpa]Z
,5|&A
String sURL; //File URL j<Bkj/
long nStartPos; //File Snippet Start Position )we}6sE"
long nEndPos; //File Snippet End Position .}q&5v
int nThreadID; //Thread's ID o<[#0T^K
boolean bDownOver = false; //Downing is over |_] Q$q[[%
boolean bStop = false; //Stop identical X#*JWQO=
FileAccessI fileAccessI = null; //File Access interface U>cV|
\!k1a^ZP
H7d/X
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException zbk q
{ J&M o%"[)
this.sURL = sURL; t/cY=Wp
this.nStartPos = nStart; j7jCm:
this.nEndPos = nEnd; ;%<,IdhN
nThreadID = id; 6kNrYom
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !9[>L@#G
} )+[ gd/<C.
P0W*C6&71|
iH/6M
public void run() d{SG Cr 9d
{ Jth[DUH8H
while(nStartPos < nEndPos && !bStop) n@C[@?D
{ W+PJZn
x c/}#>ED
E7.2T^o;M
try{ Hkwl>R$
URL url = new URL(sURL); ^Pbk#|$rU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q4+gAS9
httpConnection.setRequestProperty("User-Agent","NetFox"); LcUh;=r}&
String sProperty = "bytes="+nStartPos+"-"; |y0(Q V
httpConnection.setRequestProperty("RANGE",sProperty); ~$)2s7 O
Utility.log(sProperty); L1cI`9
\P.I)n`8 y
q(`/Vo4g(
InputStream input = httpConnection.getInputStream(); Xc?&_\. +
//logResponseHead(httpConnection); .?R!DYC`
T)H{
H5Z$*4%G
byte[] b = new byte[1024]; $,,op(
int nRead; P*FMwrJj>r
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) IF44F3(V4
{ "uaMk}[ <!
nStartPos += fileAccessI.write(b,0,nRead); lfqiyYFm
//if(nThreadID == 1) 9y<*8bI
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9~p[
} L<ue$'
Dp)=0<$y
sg$rzT-S4
Utility.log("Thread " + nThreadID + " is over!"); gj*+\3KO@a
bDownOver = true; 1JztFix
//nPos = fileAccessI.write (b,0,nRead); aX5 z&r:{
} .(^ ,z&
catch(Exception e){e.printStackTrace ();} f33l$pOp
} ] lrWgm
} n[G&ksQI
"Y~:|?(@-
>'&p>Ad)
//打印回应的头信息 cc~O&?)i
public void logResponseHead(HttpURLConnection con) n=y[CKS
{ 4\Tl\SZ?
for(int i=1;;i++) P} 0%-JC
{ v":x4!kdX
String header=con.getHeaderFieldKey(i); mt,OniU=Q
if(header!=null) 0=AVW`J
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B56L1^7
Utility.log(header+" : "+con.getHeaderField(header)); !,6c ~ w
else FB{KH .
break; -OapVac
} ;<j0f~G`
} yCVI\y\B
@~YYD#'vNY
\$*7 >`k
public void splitterStop() ]x(e&fyHB
{ 5N/%v&1
bStop = true; 3|'>`!hb
} #~C]ZrK
xI($Uu}S
/5Oa,NS7
} 1*9U1\z
8,?h~prc
{q`jDDM
/* +yk24 `>
**FileAccess.java g*03{l#P
*//文件访问(定位，写) 6L"%e!be6
package NetFox; Z0Vl+
import java.io.*; , udTvI
}bdmomV
+ HK8jCa
public class FileAccessI implements Serializable{ #xX5,r0
B0dQ@Hq*
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 a&c6.#E{y
RandomAccessFile oSavedFile; 925|bX6I
long nPos; }BZ"S-hZ
KKiE@_z
18+)`M-5o
public FileAccessI() throws IOException l49*<nkmq
{ NQ(1
this("",0); WtG~('g>&
} @+Si?8\
BJM.iXU)[
`*_mP<Ag
public FileAccessI(String sName,long nPos) throws IOException [lWQ'DZ
{ lDYyqG4
oSavedFile = new RandomAccessFile(sName,"rw"); i rU 6D
this.nPos = nPos; Y }$/e
oSavedFile.seek(nPos); ow_W%I=6
} {2=jAz'?
A OISs4
9x>d[-#y:J
public synchronized int write(byte[] b,int nStart,int nLen) -likj#Z
{ y\Ic@-aWI
int n = -1; m1B+31'>^
try{ :N4t49i
oSavedFile.write(b,nStart,nLen); Z4S!NDMm~
n = nLen; ~<_2WQ/$
} *h!28Ya(~
catch(IOException e) r+":'/[x
{ rH_\d?b
e.printStackTrace (); }1Gv)l7
} Cd,jDPrw
FbS|~Rp~
gW>uR3Ca4
return n; gQ'zW
} oU056
g!lWu[d
:S<f?* }:
} gl\\+VyU
/?@3.3sl_
pGJ>O/%
/* %?}33yV
**SiteInfoBean.java i~I%D%;
*/ 2NC.Z;
package NetFox; bCo7*<I4
fZ0M%f
=G7m)!
public class SiteInfoBean { cq}EZ@ .
}uJu>'1[G
*5%d XixN
private String sSiteURL; //Site's URL =Je[c,&j$?
private String sFilePath; //Saved File's Path tnH2sHby
private String sFileName; //Saved File's Name $*e2YQdLo
private int nSplitter; //Count of Splited Downloading File `UD/}j@
/|tJ6T1LrB
AK'[c+2[
public SiteInfoBean() Fq|Ni$
{//nSplitter的缺省值为5 z\K"Rg~J
//default value of nSplitter is 5 41`n1:-]
this("","","",5); R=gb'
} ,\_1w
,K9*%rW)
WI-&x '
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) % tS,}ze
{ /t+f{VX$
sSiteURL= sURL; O(fM?4w
sFilePath = sPath; 7gf05Z'=
sFileName = sName; hQYL`Dni
this.nSplitter = nSpiltter; D{GfLib"U
F*IzQ(#HW
>AVVEv18
} vdAr|4^qB
,:%CB"J
"W6uV!
public String getSSiteURL() ',9V|jvK
{ 't:;irLW.
return sSiteURL; OI|[roMK
} ojaws+(& y
>_[9t
t^+ik1.
public void setSSiteURL(String value) );#JL0I
{ mk.9OhYY
sSiteURL = value; uatm/o^~,
} l4F%VR4KT
2BQ j
Cn,d?H
public String getSFilePath() g;pcZ9o
{ s'!Cp=xQF"
return sFilePath; d' !]ZWe
} RIlwdt
]~9tYn
/rK}?U
public void setSFilePath(String value) (?n=33}Ci
{ uGwm r
sFilePath = value; 6n,i0W
} |:nn>E}ZA/
cz >V8
5eLtCsHz
public String getSFileName() q ?|,O;?
{ |cK*~
return sFileName; vx>b^tJKC
} `7c~mypx
00(on28b
cr%"$1sY;
public void setSFileName(String value) gwLf'
{ YmL06<Mh
sFileName = value; NP0\i1P>.?
} T$>WE= Y
i6^twK)j
}JF13beU
public int getNSplitter() 3 }duG/
{ [$mHv,~
return nSplitter; /KFfU1
} SWH2
j_K4;k#r
@Xt*Snd
public void setNSplitter(int nCount) PC~Y8,A|.t
{ bGN:=Y'
nSplitter = nCount; 6Y^23W F
} &*##bA"!B
} <fZyAa3}
?^7t'`zk
aRj9E}
/* $Ipg&`S"
**Utility.java I@T8Iv=
*/ Z_$%.
package NetFox; C^O VB-
=O&%c%~q
(7vF/7BZ|_
public class Utility { HHA<IZ#;,
52%2R]G!
vmU@^2JSJ
public Utility() Z?6%;n^ 54
{ 5&QJ7B,!
MX$0Op
caU0\VS
} '9laa=H%8
fa-IhB1!K
//线程睡眠 qB~rQPa
public static void sleep(int nSecond) \z>fb%YW
{ `nUXDmdwzO
try{ ),0g~'I~D
Thread.sleep(nSecond); d?ex,f.
} gR&Q3jlIV
catch(Exception e) SzAJ2:qhl
{ ! +a.Ei
e.printStackTrace (); y=fx%~<> 8
} G/k2Pe{SL
} vleS2-]|
XeW<B0~
//日志 6g2a[6G5
public static void log(String sMsg) S'k_olx7
{ I&2c&yO
System.err.println(sMsg); IshKH-
} 'KP@W9j
n&L+wqJ
4;w;'3zq
public static void log(int sMsg) sQ=]NF)\
{ hB"fhX
System.err.println(sMsg); {Bk[rCl
} u__9Z:+
} s(5Y
]GMe\n
jfP*"uUK
/* rxe>}ZO
**TestMethod.java ,-$LmECg
*/ 9eGyyZg
package NetFox; 4qO+_!x{)
6w*dKInG[-
x/NfZ5e0X
public class TestMethod { QCD.YFM
EOIN^4V"
cbNTj$'b2u
public TestMethod() F5LuSy+v
{ ///xx/weblogic60b2_win.exe l>2E (Y|
try{ $~~Jw]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); p2Z?T}fa}&
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "An,Q82oHf
SiteFileFetch fileFetch = new SiteFileFetch(bean); z#zI1Am(O
fileFetch.start(); NvD7Krqwa
} Qk0R a_
catch(Exception e){e.printStackTrace ();} D|lzGt
Y#]+Tm(+
-j+UMlkB
} 4~ q5,^kgB
[^R^8k
b[sx_b
public static void main(String[] args) XtXEB<4Z
{ 8Ry3`ct
new TestMethod(); &x=.$76
} F<ZYh
} 7yG#Z)VE
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