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)); ',kYZay
} vj[ .`fY
for(int i=0;i<nEndPos.length-1;i++) $62ospR^Y
{ V`S6cmwdc\
nEndPos = nStartPos[i+1]; GZXUB0W\@)
} uzho>p[ae
nEndPos[nEndPos.length-1] = nFileLength; H`),PY2
} WSi Utf|g
} DD"]as"#
G:c)e,pD
*@cXBav/<
//启动子线程 b&HA_G4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; cEve70MV
for(int i=0;i<nStartPos.length;i++) h+,zfVJu
{ 2B=yT8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :~zK0v"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9i yNR!
nStartPos,nEndPos,i); UR1U; k
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7AV!v`
fileSplitterFetch.start(); u{ JAC!
} T1M4@j
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8.{5c6G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); NLoJmOi;L7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", rm+|xvZ4
nEndPos = " + nFileLength); BGLJ>zkq
// fileSplitterFetch[nPos.length-1].start(); `cy_@Z5A
+7^%fX;3pW
P9G c)$6{p
//等待子线程结束 a&.8*|w3
//int count = 0; 35B0L.R
//是否结束while循环 5z5#_*)O
boolean breakWhile = false; 2o6KVQ
^Ml)g=Fq
;5PXPpJ
while(!bStop) tP"C>#LO
{ zK k;&y|{
write_nPos(); Iy8Ehwejd
Utility.sleep(500); \uQ(-ji
breakWhile = true; 2e/ JFhA
DFVaZN?~
^7Z)/c`"
for(int i=0;i<nStartPos.length;i++) jU@qQ@|
{ J6n@|L!yO
if(!fileSplitterFetch.bDownOver) (](:0H
{ ,m8l /wG
breakWhile = false; \gDf&I
break; jC@$D*"J
} ou6yi; l%
} @4sv(HyDY
if(breakWhile) (05/}PhB`
break; 2%. A{!
oa}-=hG
A=I]1r
//count++; }_@*,
//if(count>4) 9=ns.r
// siteStop(); Xb?P'nD
} ?`uY*+u
Eu l,1yR
(6^v`SZ
System.err.println("文件下载结束！"); Al5E
} rs]%`"&=
catch(Exception e){e.printStackTrace ();} yS@c2I602
} q$(aMO&J
k9~NIvnB`
!L2R0Y:a
//获得文件长度 L1VUfEG-
public long getFileSize() l"f.eo0@7
{ d2Z5HFtY
int nFileLength = -1; Y]Vt&*{JV
try{ u+&BR1)C
URL url = new URL(siteInfoBean.getSSiteURL()); 7!]$XGz[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0x4Xs
httpConnection.setRequestProperty("User-Agent","NetFox"); ]p\7s
)U`6` &F
\5_+6
int responseCode=httpConnection.getResponseCode(); 3 i Id>
if(responseCode>=400) (]w_}E]N
{ Dwj!B;AZ_
processErrorCode(responseCode); "|{NRIE
return -2; //-2 represent access is error (Dlh;Ic r9
} $.a<b^.Xi
o:.={)rX
~4"adOv
String sHeader; P%8 Gaa=
sG=D(n1
?w#V<3=
for(int i=1;;i++) ^vn8s~#
{ aqQ YU5l4~
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6y)TXp
//Utility.log(in.readLine()); 47|Lk]+O
sHeader=httpConnection.getHeaderFieldKey(i); n;@PaE^8=
if(sHeader!=null) W-qec
{ "T=Z/@Vy
if(sHeader.equals("Content-Length")) "_eHK#)
{ MRR5j;4GK
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $]2srRA^A
break; Q>8F&p?R
} "9'~6b
} GbUw:I
else DJVH}w}9_P
break; x{6KsYEY
} ,)TtI~6Q
} qsOA(+ZP
catch(IOException e){e.printStackTrace ();} JR8 b[Oj.S
catch(Exception e){e.printStackTrace ();} wN>k&J
k|k
[CL.Xil=
Utility.log(nFileLength); EiQX*v
9utiev~3
4nK\gXz19
return nFileLength; {;4Y5kj
} j]U sb_7
29("gB
9^6E>S{=
//保存下载信息（文件指针位置） b#`XmB
private void write_nPos() VkTdpeBV
{ 7I;xRo|
try{ NRN3*YGo
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9>yLSM,!rS
output.writeInt(nStartPos.length); M<s16
for(int i=0;i<nStartPos.length;i++) 4[m})X2(
{ /j/,@,lw7z
// output.writeLong(nPos); )9I>y2WU~
output.writeLong(fileSplitterFetch.nStartPos); Aslh}'$}-
output.writeLong(fileSplitterFetch.nEndPos); #5)0~4%l
} KJn@2x6LP
output.close(); Ir&rTGFN
} }(k#,&Fv`
catch(IOException e){e.printStackTrace ();} TUHm.!+a
catch(Exception e){e.printStackTrace ();} B~+3<#B
} +Z> Y//
,cZhkXd
l/1u>'
//读取保存的下载信息（文件指针位置） GKT2x '(e
private void read_nPos() _&V%idz!0
{ &.XlXihnt
try{ POvxZU
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8=QOp[w
int nCount = input.readInt(); c%y(Z5
nStartPos = new long[nCount]; vT/e&8w
nEndPos = new long[nCount]; P 4Vi~zMX
for(int i=0;i<nStartPos.length;i++) <7'`N\a
{ !"1}zeve
nStartPos = input.readLong(); Y-!~x0-H
nEndPos = input.readLong(); KYE)#<V}@
} 1 aWzd[i
input.close(); rPhx^ QKH2
} PD #9Z=Hj
catch(IOException e){e.printStackTrace ();} EQe!&;
catch(Exception e){e.printStackTrace ();} "NEg]LB5
} 8T6LD
!dnCrR
g)0>J
private void processErrorCode(int nErrorCode) YnM&t ;TX
{ w-iu/|}
System.err.println("Error Code : " + nErrorCode); X$*MxMNs
} Pq\ `0/4_
L\0;)eJ#M
N>ncv
//停止文件下载 w>#{Nl7gz
public void siteStop() ot\ FZ
{ ;f;A"
bStop = true; q4u,pm,@
for(int i=0;i<nStartPos.length;i++) m=Mb'<
fileSplitterFetch.splitterStop(); (V&5EO8)
a8 X}r.
e"}JHXs
} ba5,?FVI~
} o\/&05rp]
//负责部分文件的抓取 /{1sU}k-
**FileSplitterFetch.java yyPQ^{zD
*/ "PgVvm#w'
package NetFox; &10l80vj
M3XG s|gw
?^Gi;d5
import java.io.*; ?'_Ty`vT
import java.net.*; Cws;6i*=@
s!k7Wwj
G5WQTMzf&
public class FileSplitterFetch extends Thread { d]A.=NAc
PP*6nW8
u<L<o2
String sURL; //File URL Sg%h}]~
long nStartPos; //File Snippet Start Position wnioIpRkh
long nEndPos; //File Snippet End Position CdBpz/
int nThreadID; //Thread's ID aE|'%72g
boolean bDownOver = false; //Downing is over 0Q7teXRM
boolean bStop = false; //Stop identical ( p(/
FileAccessI fileAccessI = null; //File Access interface yMG(FAyu
8F>u6Y[P
(Q5rOrA"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException R*[X. H
{ 9Lus,l\
this.sURL = sURL; :g%hT$,]3b
this.nStartPos = nStart; N5PW]
this.nEndPos = nEnd; -L-#-dK'
nThreadID = id; Ky0}phGRu
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2xLEB&
} ^VC/tJ
# &,W x
}Q2v~eD
public void run() 7xF)\um
{ ]?< wUd
while(nStartPos < nEndPos && !bStop) U g:
{ *S xDwN
awXK9}.
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try{ HNJR&U t
URL url = new URL(sURL); RWg'W,v=!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /^]/ iTg
httpConnection.setRequestProperty("User-Agent","NetFox"); Z";&1cK
String sProperty = "bytes="+nStartPos+"-"; ` 0$i^,}
httpConnection.setRequestProperty("RANGE",sProperty); zqHG2:MN"
Utility.log(sProperty); OV G|WC
0g2?
Iuyq!R4:7
InputStream input = httpConnection.getInputStream(); }/w]+f*
//logResponseHead(httpConnection); m?<^b_a}
~8 B]
{+~ JTrp
byte[] b = new byte[1024]; '[Sm w'n6-
int nRead; |}7!'f\M
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) MzFFWk
{ DsB30
nStartPos += fileAccessI.write(b,0,nRead); Ucx"\/"
//if(nThreadID == 1) z!M #
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); I4|LD/b
} xH\!j
eJ*u]GH U
ZveNe~D7C
Utility.log("Thread " + nThreadID + " is over!"); `q9n`h1
bDownOver = true; eMV{rFmT
//nPos = fileAccessI.write (b,0,nRead); k vpkWD;
} e#U@n j6
catch(Exception e){e.printStackTrace ();} ;AG&QdTMh
} tj?%{L
} r|63T%q!
HA J[Y3d<
)3 I~6ar
//打印回应的头信息 O#<F"e;$
public void logResponseHead(HttpURLConnection con) A`--*$8\
{ +CVB[r#hu
for(int i=1;;i++) Dm@h'*
{ Z0/$XS9|h;
String header=con.getHeaderFieldKey(i); |KR8=-!7
if(header!=null) lak,lDt]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~.tl7wKkR/
Utility.log(header+" : "+con.getHeaderField(header)); \.aKxj5
else 4tEAi4H|`@
break; NXk~o!D
} eZoAy[
} fikDpR
4]HW!J
LOgFi%!6:
public void splitterStop() d5>EvK U
{ t~H0Qeb[v=
bStop = true; '3w%K+eJY
} YV8PybThc
#bJp)&LO
.=)[S5.BVq
} ~,_@|,)
BbM/Rd1tAm
1V wcJd
/* _!_^B
**FileAccess.java 'yosDT2{#
*//文件访问(定位，写) Hd\.,2a"
package NetFox; f}~=C2R1<!
import java.io.*; Q#X'.](1
p+pu_T;~
A^E 6)A=
public class FileAccessI implements Serializable{ r#A*{4wz
S0Ur{!9\#^
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !{4'=+
RandomAccessFile oSavedFile; )7{r8a
long nPos; pw&k0?K#
L PS,\+
g[R4/]K^$
public FileAccessI() throws IOException it-]-=mqb
{ 2FW"uYA;6
this("",0); 2z.~K&+x
} )QWhzY
a)4%sX*I
.EPv4[2%F8
public FileAccessI(String sName,long nPos) throws IOException Qqi?DW1)-
{ Z4X, D`s
oSavedFile = new RandomAccessFile(sName,"rw"); l1#.rg
this.nPos = nPos; qqJghV$Oj
oSavedFile.seek(nPos); M}j[{wW3
} JljCI@
2">de/jS
^D]J68)#a
public synchronized int write(byte[] b,int nStart,int nLen) t 9t '9
{ #1C]ZV] B
int n = -1; eIEL';N6
try{ ?S'aA!/;
oSavedFile.write(b,nStart,nLen); >S-JAPuO
n = nLen; v`c;1?=,q
} eh%{BXW[p
catch(IOException e) @`#x:p:
{ hj&~Dn(
e.printStackTrace (); z`YC3_d
} 5*f54g"'
mlCBstt{
L }3eZ-
return n; d``wx}#Uk
} tot~\S
QFnpp\K
qe'ssX;
} )7]yzc
SuB8mPn
gTgoS:M"_O
/* +I-BqA9
**SiteInfoBean.java kh{3s:RQfC
*/ C=|8C70[%N
package NetFox; {=\Fc`74
B;F~6i
ahIDKvJ4
public class SiteInfoBean { ij|>hQC5i
w[D]\>QHa
p!~1~q6
private String sSiteURL; //Site's URL ZDAW>H<
private String sFilePath; //Saved File's Path ).IyjHY
private String sFileName; //Saved File's Name vBJxhK-
private int nSplitter; //Count of Splited Downloading File dC8}Ttc}
*`|xa@1v`
,[T/O\k
public SiteInfoBean() \m~p;B
{//nSplitter的缺省值为5 *sZH3:
//default value of nSplitter is 5 6-uLK'E
this("","","",5); -)B_o#2=2
} gwsIzYV
PqL.^
Qclq^|O0
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Y8^WuN$
{ j#2EQ
sSiteURL= sURL; u]7wd3(
sFilePath = sPath; dWQB1Y*N
sFileName = sName; !V(r p80
this.nSplitter = nSpiltter; s*_fRf:
dHTx^1
;2\6U;
} W8$0y2
122s7A
JBLUX,
public String getSSiteURL() <&3aP}
{ ez!W0
return sSiteURL; ^H7xFd|>
} -|^)8
GA$fueiQNs
a;^lOU|L{
public void setSSiteURL(String value) g`Cv[Pq?at
{ $/|) ,n
sSiteURL = value; HzKY2F(,
} "oNl!<ep
UKZ)Boo
z6l'v~\
public String getSFilePath() 8PH4v\tJEK
{ mNacLkh[
return sFilePath; In?#?:Q@&
} pqb`g@
|,5|ZpgL
oQ,<Yx%E3
public void setSFilePath(String value) v*qbzW`
{ -aVC`
sFilePath = value; ZZZ9C#hK^9
} b=xn(HE8|
.gmS1ju
0+$gR~^^
public String getSFileName() s2NBYDi$?
{ c?EvrtND
return sFileName; 7(X z%v
} GM'yOJo
YI;iG[T,&
G"E_4YkJ
public void setSFileName(String value) >;hAw!|#
{ i>,AnkI&
sFileName = value; ~gW^9nWYU
} d)bsyZ;U
7L6L{~8 W
A"&<$5Q
public int getNSplitter() CxjB9#
{ Xpn\TD<_I
return nSplitter; [2Zy~`*y{
} 0QW=2rs
wiZ
!rr,(!Ip?O
public void setNSplitter(int nCount) hL6;n*S=
{ ~gff{Nzk
nSplitter = nCount; o h\$u5
} %+Ze$c}X
} Tn1V+)
}.E^_`
,0,FzxX0!
/* abT,"a\h
**Utility.java =WW5H\?
*/ $.,B2}'
package NetFox; >@Ht*h{~
qf\W,SM
?.%dQ0
public class Utility { SU4i'o
]#^v754X^T
tx>7?e8E
public Utility() E5)0YYjHZ
{ 9l&q}
6V]m0{:E
:,aY|2si
} Sk>=C0f:
!|xB>d q?
//线程睡眠 t~j6wsx;
public static void sleep(int nSecond) \q1tT!]
{ <MkvlLu((o
try{ ~Ay)kv;
Thread.sleep(nSecond); HrvyI)4{
} WIf.;B)L
catch(Exception e) [UI>SN
{ <6Gs0\JB
e.printStackTrace (); >h;]rMD!|
} :tU^
} 4k@n5JNa
>d p/
//日志 >bze0`}Z
public static void log(String sMsg) 0t^FM<7G
{ dGBjV #bNT
System.err.println(sMsg); e~zgH\`
} rY45.,qWs
mLZ1u\7W
G@`F{l
public static void log(int sMsg) 4/`;(*]Fv
{ Z>g>OPu
System.err.println(sMsg); rx2'].
} CL1*pL
} |*NZ^6`@
)/>BgXwH
O;<wDh)Yt
/* M['O`^
**TestMethod.java 77O$^fG2
*/ 3PU_STSix
package NetFox; /"?DOsJ.
W<prY
8(\}\4G_
public class TestMethod { cZ:jht
(b f IS
gPMfn:a-8
public TestMethod() bp:`m>4<
{ ///xx/weblogic60b2_win.exe Mww^
try{ \(j*K6#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); .yZLC%}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); dE_Xd:>
SiteFileFetch fileFetch = new SiteFileFetch(bean); lEFd^@t
fileFetch.start(); H575W"53
} 0<\|D^m=&h
catch(Exception e){e.printStackTrace ();} R#4l"
1$vGQ
OA3J(4!"W
} 6(`N!]e*L
<N=k&\
YJ6~P
public static void main(String[] args) T[|#DMg$F
{ !2Nk
new TestMethod(); )DXt_leLg
} <3B^5p\/
} /"gRyv
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