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)); +7^{T:^ht
} .0r5=
for(int i=0;i<nEndPos.length-1;i++) +|r) ;>b
{ n!A')]y"
nEndPos = nStartPos[i+1]; v6;XxBR6
} @| qnD
nEndPos[nEndPos.length-1] = nFileLength; `N;u#z
} 5d<-y2!M
} coiTVDwA
j"yL6Q9P
v5RS<?o
//启动子线程 _LxV)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Yk6fr~b
for(int i=0;i<nStartPos.length;i++) 's(0>i
{ >5i1M^g(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m%'9zL c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), HkGzyDt
nStartPos,nEndPos,i); g=:%j5?.e
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jrvhTej
fileSplitterFetch.start(); av&dGsFP
} 9Or3X/:o
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !s9<%bp3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `9kjYSd#E
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Z#3wMK~
nEndPos = " + nFileLength); fZ 17
// fileSplitterFetch[nPos.length-1].start(); e}-uU7O
)|q,RAn
RHz'Dz>0
//等待子线程结束 VsNqYFHes&
//int count = 0; ?so3Kj6H
//是否结束while循环 T<mk98CdE
boolean breakWhile = false; K&Ht37T
9L*gxI>
,iB)8Km@U
while(!bStop) mAX]m1s
{ )U`H7\*)
write_nPos(); kS[k*bN0
Utility.sleep(500); pzCD' !*
breakWhile = true; uZW ?0W
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4Q,HhqV'
for(int i=0;i<nStartPos.length;i++) -~p@o1k0
{ (TDLT^
if(!fileSplitterFetch.bDownOver) NV^ktln
{ (IAl$IP63s
breakWhile = false; h,\^Sb5AP
break; pIqPIuy
} 1e _V@Vy
} +d2+w1o^V
if(breakWhile) 3Yp_k
break; OHR9u
V89!C?.[]1
Q{0-pHr}
//count++; ZL+{?1&-
//if(count>4) Wu2#r\
// siteStop(); T=A7f6`
} LrsP4G
7?]gUrE
jcYI"f"~
System.err.println("文件下载结束！"); ;_F iiBk7(
} r%&hiobMYs
catch(Exception e){e.printStackTrace ();} sYYg5vL9
} BT2[@qH|qF
+wY3E*hU
)Mi#{5z
//获得文件长度 T=ox;r
public long getFileSize() +7|Oy3s
{ BO#fzq%
int nFileLength = -1; CDO_A\
try{ MVe5j+8
URL url = new URL(siteInfoBean.getSSiteURL()); IhJ _Yed
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v7\~OOoH]
httpConnection.setRequestProperty("User-Agent","NetFox"); *J 7>6N:-
s^AQJ{X
%$:js4
int responseCode=httpConnection.getResponseCode(); st:[|`
if(responseCode>=400) M#=woj&[
{ Vj:)w<],
processErrorCode(responseCode); 7Aq4YjbX
return -2; //-2 represent access is error ]zhFFq`
} ^pKC0E[%
o{f n}
X:j&+d2g0/
String sHeader; ?P4`
jQ4Pv`
=3a`NO5!
for(int i=1;;i++) H) m!)=\'
{ o//N"S.)
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); kVe^g]F
//Utility.log(in.readLine()); s><RL]+{G+
sHeader=httpConnection.getHeaderFieldKey(i); H_o<!YxK
if(sHeader!=null) &j2L-)
{ V<\:iNXX{
if(sHeader.equals("Content-Length")) b0rC\^x
{ A:cc @ku
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); z }R-J/xr2
break; q^n6"&;*
} {>5z~OV
} V.1sb pI
else ~*LH[l>K
break; R 7xV{o
} lh(A=hn"n
} 5u~Ik c~
catch(IOException e){e.printStackTrace ();} kFw3'OZ,
catch(Exception e){e.printStackTrace ();} {1#5\t>9yD
Nr|.]=K)5n
-XPGl
Utility.log(nFileLength); o5BOe1_Pw
~.VWrHC
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return nFileLength; x|F6^d
} E-E+/.A
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fx99@%Ii
//保存下载信息（文件指针位置） S]K^wj[
private void write_nPos() ]m=* =LLC
{ R)nhgp(~
try{ Mf%/t HK
output = new DataOutputStream(new FileOutputStream(tmpFile)); /fBZRdB
output.writeInt(nStartPos.length); wI#rAx7f-
for(int i=0;i<nStartPos.length;i++) (x&#>5
{ 9/~m837x
// output.writeLong(nPos); ^Ac0#oX]M
output.writeLong(fileSplitterFetch.nStartPos); pZlBpGQf
output.writeLong(fileSplitterFetch.nEndPos); %vxd($Ti"
} 1Q#hanh_`
output.close(); ?9Fv0-g&n
} 9P{5bG0o8
catch(IOException e){e.printStackTrace ();} K)_0ej~C
catch(Exception e){e.printStackTrace ();} =y0!-y
} lBD{)Va
yE{l Xp;
zp% MK+x
//读取保存的下载信息（文件指针位置） t=xO12Z
private void read_nPos() !`=r('l
{ uvc0"g1h
try{ C/<fR:`c
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); v srce
int nCount = input.readInt(); ;s9!ra:3
nStartPos = new long[nCount]; X'7 T"5!
nEndPos = new long[nCount]; cK@O)Ko}
for(int i=0;i<nStartPos.length;i++) :2 QA#
{ Y^2Ma878
nStartPos = input.readLong(); :M1+[FT
nEndPos = input.readLong(); y{!`4CxF
} &{Uaa
input.close(); dQ/Xs.8
} K4,VSy1byI
catch(IOException e){e.printStackTrace ();} i:qc2#O:J
catch(Exception e){e.printStackTrace ();} 0}Kl47}aD
} p KKn
[9[tn-
|pq z(j7
private void processErrorCode(int nErrorCode) kYPowM
{ YRW<n9=3
System.err.println("Error Code : " + nErrorCode); jM2gu~
} oJ{)0;<~L
Z TjlGU `
""d3ownKhw
//停止文件下载 4)/tCv
public void siteStop() a9FlzR
{ B,e@v2jO|
bStop = true; j(va#f#
for(int i=0;i<nStartPos.length;i++) gRSM~<
fileSplitterFetch.splitterStop(); [MFV:Z
P@k ;Lg"
*Ty>-aS1
} n." j0kc7=
} S9U9;>g
//负责部分文件的抓取 }gag?yQ.^
**FileSplitterFetch.java Y($"i<rN
*/ /e4hB
package NetFox; Qy0bp;V/
!%T@DT=l&
&b"PjtU.X
import java.io.*; /5U?4l(6[f
import java.net.*; /3FC@?l w4
5IVASqYp
X k<X:,T
public class FileSplitterFetch extends Thread { sJ3HH0e
<9\_b6
zh*NRN
String sURL; //File URL hh:0m\@<
long nStartPos; //File Snippet Start Position _Xsn1
long nEndPos; //File Snippet End Position i"Ct}7i
int nThreadID; //Thread's ID "W\ #d
boolean bDownOver = false; //Downing is over &NHIX(b6
boolean bStop = false; //Stop identical D2>=^WP6+
FileAccessI fileAccessI = null; //File Access interface "84.qgYaG
OwSr`2'9
SV6Np?U
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +qzsC/y
{ M"X/([G
this.sURL = sURL; "=P@x|I
this.nStartPos = nStart; N{|N_}X`Y
this.nEndPos = nEnd; He">kJx
nThreadID = id; }I05&/o.3p
fileAccessI = new FileAccessI(sName,nStartPos);//定位 pOnZ7(
} >jN)9}3>-#
+]5JXt^
)JeiTh^
public void run() M;\K+,
{ *Z)`:Gae
while(nStartPos < nEndPos && !bStop) ME0ivr*=:
{ "9>#Q3<N
-bZ^A~<O,
|Vd)7/LN
try{ .$99/2[90
URL url = new URL(sURL); uh:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |{t}ULc
httpConnection.setRequestProperty("User-Agent","NetFox"); %ze Sx
String sProperty = "bytes="+nStartPos+"-"; %z.u % %
httpConnection.setRequestProperty("RANGE",sProperty); JGGss5
Utility.log(sProperty); (8=Zr0He
;<ed1%Le,
oVc_(NH-
InputStream input = httpConnection.getInputStream(); <aL$d7
//logResponseHead(httpConnection); X@|
ro^Y$;G
bG2!5m4L
byte[] b = new byte[1024]; 7v%~^l7:x
int nRead; ~q-|cl<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) W9a H]9b
{ &W".fRH_O
nStartPos += fileAccessI.write(b,0,nRead); TO3Yz3+A
//if(nThreadID == 1) &*/X*!_HK
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EG<K[t
} pm3?
;}^Pfm8
J~n{gT<L
Utility.log("Thread " + nThreadID + " is over!"); 'T+3tGCy+
bDownOver = true; P(A%z2Ql
//nPos = fileAccessI.write (b,0,nRead); NrS1y"#d9
} 3YA !2
catch(Exception e){e.printStackTrace ();} urXM}^
} ?\ho9nyK
} |W\CV0L2
Vj~R6
I-fs*yzj;8
//打印回应的头信息 ,+zLFQC0@
public void logResponseHead(HttpURLConnection con) ZFz>" vt@
{ Bv3?WW
for(int i=1;;i++) NpH)K:$#%
{ QFDjsd4
String header=con.getHeaderFieldKey(i); *$(9,y\
if(header!=null) -I\_v*nA
//responseHeaders.put(header,httpConnection.getHeaderField(header)); mIl^
Utility.log(header+" : "+con.getHeaderField(header)); bLaD1rnGi
else l3l[jDa,2
break; [dOPOA/d
} F4">go
} Z1^S;#v
?A,gDk/#
8.]dThaq
public void splitterStop() vP88%I;
{ 2 B5kpmH:
bStop = true; @f{)]I +f
} [4t_ 83
i"sVk8+o!
"+saI@G
} .o.@cLdU
jf.ikxm
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/* 8l;0)`PU
**FileAccess.java jG{xFz>x
*//文件访问(定位，写) pwU]r
package NetFox; Y @pkfH
import java.io.*; 7m@pdq5Ub
"+Xwc+v^
RQ}x7</{
public class FileAccessI implements Serializable{ :jB(!XH
,ulTZV
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 p5G O@^i
RandomAccessFile oSavedFile; |MTgKEsn
long nPos; Tje =vI
a] >|2JN<&
Njz,y}\
public FileAccessI() throws IOException `=%[
{ _qJ[~'m<^C
this("",0); _Ndy;MQ
} w#XE!8`
P#rwYPww\
URJ"
public FileAccessI(String sName,long nPos) throws IOException LNk 3=v2M
{ 1pO ;aG1O
oSavedFile = new RandomAccessFile(sName,"rw"); q:1 1XPP
this.nPos = nPos; 6t/})Xv
oSavedFile.seek(nPos); I2K52A+
} HmRwh
OXA_E/F
%#ms`"H
public synchronized int write(byte[] b,int nStart,int nLen) l<z[)fE{uS
{ Kq6m5A]z
int n = -1; ~iF*+\
try{ p~Dm3^Y
oSavedFile.write(b,nStart,nLen); UxD1+\N6?
n = nLen; +zz9u?2C`
} >JCSOI
catch(IOException e) OdwSNG
{ +<bq@.x
e.printStackTrace (); McH*J j
} D95$
V/>SjUNq
v`x~O+
return n; ^/Gjk
} Mk,8v],-Tj
kDO6:sjR7
fbo64$!hZ
} `acorfpi
:M|bw{P*
+=u*!6S
/* eQ9{J9)?
**SiteInfoBean.java br$!}7#=L
*/ ^Fb"Is#S,
package NetFox; cr,o<
3S'V>:
R%3H"FU9w
public class SiteInfoBean { |W*f6F3
!!Mp;h'}-
#8nF8J<4
private String sSiteURL; //Site's URL 9OT2yCT
private String sFilePath; //Saved File's Path &\Cvrxa
private String sFileName; //Saved File's Name ecf<(Vl}
private int nSplitter; //Count of Splited Downloading File >[ 72]<6
3^1)W!n/
SL@Vk(
public SiteInfoBean() fVR ~PG0
{//nSplitter的缺省值为5 hTVN`9h7
//default value of nSplitter is 5 T']*h8
this("","","",5); NF&\<2kX
} 2Ni{wg"
VFA1p)n
s/Q}fW$ex
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -uO< ]
{ :CK,(?t
sSiteURL= sURL; pklcRrx,a
sFilePath = sPath; )S8q.h
sFileName = sName; >KGQ#hnH
this.nSplitter = nSpiltter; f()^^+
vbwEX6
;}|.crMF
} r\=p.cw<
y7,~7f!N2
>]C;sP
public String getSSiteURL() -!;vX @
{ _;LHC;,:
return sSiteURL; b2p<!?
} DB?_E{y]
]V.9jlXF
m{+lG*
public void setSSiteURL(String value) ax7 M
{ Z.<1,EKi=
sSiteURL = value; +H="5uO<
} ?]h+En5z8
2$1rS}}
Ej.D!@
public String getSFilePath() :nZ*x=aq
{ 0Vy* 0\{S
return sFilePath; j#!J hi
} s/ZOA[Yux
%R&3v%$y*
ZMx_J
public void setSFilePath(String value) ?{{E/J:%
{ .iew5.eB+
sFilePath = value; zq1&MXR)l
} @X\nY</E#M
g`J? 2 _]
"OK(<x]3;>
public String getSFileName() JZP2NB_xt
{ -*yj[?6
return sFileName; Iun!rv
} ap;UxWqx
mT-5Ok&TUe
g3x192f
public void setSFileName(String value) RJtSHiM2
{ DC/CUKE.d
sFileName = value; +;;fw |/
} EidIi"sr
DlIfr6F
Pu axS
public int getNSplitter() T<!`~#kM
{ )(DV~1r=
return nSplitter; }T(|\ X
} 70KXBu<6
{v]>sn;P1
>O\-\L
public void setNSplitter(int nCount) 9=JU&/!
{ \vm'D'9
nSplitter = nCount; c#{<| .
} F1%' zsv
} #+_OyZ*
vZ|-VvG
I;mtyS
/* 4] DmgOru%
**Utility.java p1Lx\
*/ EQ=Enw1[
package NetFox; \=5CNe
2d1'!B zDA
"aa6W
public class Utility { 1bj75/i<6
1U"Y'y2
!' sDqBZ&7
public Utility() -@J;FjrXmP
{ 9"V27"s
8E0Rg/DnT
KE5f`h
} u $sX6
03rZz1
//线程睡眠 Y1 -cz:
public static void sleep(int nSecond) qw_qGgbl
{ _n{N3da
try{ j83p[qR7o
Thread.sleep(nSecond); G_AAE#r`
} possM'vC
catch(Exception e) 5'z&kl0"S
{ N8nyTPw
e.printStackTrace (); #Q$4EQB
} {[Yv@CpN
} yY&(?6\{<<
3q1O:b^eo
//日志 J-\b?Ra
public static void log(String sMsg) h+*
{ Q&F@[k
System.err.println(sMsg); $6'xRUx X
} W tzV|e,
b]Z@zS<8
uHf~KYL
public static void log(int sMsg) aMz%H|/$
{ wh~~g qi9
System.err.println(sMsg); ; 9'*w=V
} xaeY^"L
} nh E!Pk
\XB71DUF
FG8bP
/* Bj]0Cz
**TestMethod.java ~Q]B}qdm
*/ M#|TQa N
package NetFox; @pG\5Jnf
\8t g7Sdq
qC3 rHT]
public class TestMethod { -<s?`Rnk
<o]tW4\(R
BtqJkdK!;1
public TestMethod() ;V%lFP3#
{ ///xx/weblogic60b2_win.exe f}+G;a9Nj
try{ sxsM%Gb?H
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :*oI"U*f
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); A: @=?(lI3
SiteFileFetch fileFetch = new SiteFileFetch(bean); #lB[]2]N
fileFetch.start(); _;@kS<\N
} |r /}r,t}
catch(Exception e){e.printStackTrace ();} Gwvs~jN
2?}(
+T4<}+n
} hU4~`gp
FS@SC`~(
*y0`P0V|8
public static void main(String[] args) 8a05`ZdP
{ >w*"LZjTTK
new TestMethod(); |]`+@K,S
} {fGi:b\[ 8
} R=9j+74U
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