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)); 2PSt*(
} 6#rj3^]
for(int i=0;i<nEndPos.length-1;i++) j >wT-s
{ `K^j:fE7n
nEndPos = nStartPos[i+1]; wpLC,
} )m7 Yo
nEndPos[nEndPos.length-1] = nFileLength; PLmf.hD\
} )D1=jD(
} uNn]hl|x
.}.63T$h9
R%Y#vUmBV{
//启动子线程 ;.<0lnV
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $ }D9)&f;
for(int i=0;i<nStartPos.length;i++) yxt`
{ ]7ZY|fP2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c<gvUVHIxR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _PR><L_
nStartPos,nEndPos,i); e:&(y){n(
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); C3p/|{TP
fileSplitterFetch.start(); }L1-2
} \-?@ &' :
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), If*t$f>y4N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); v3vQfcxR
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^Q'^9M2)
nEndPos = " + nFileLength); A=5A8B1
// fileSplitterFetch[nPos.length-1].start(); *&VqAc%qD
iEJY[P1
(\=iKE4#
//等待子线程结束 OYsG#
//int count = 0; M!e$h?vB
//是否结束while循环 2Xt$KF,?
boolean breakWhile = false; ))qOsphN
4x'N#m{p
=U_WrY<F
while(!bStop) SqF9#&F
{ 9<ev]XaSl
write_nPos(); uS%Y$v
Utility.sleep(500); LmKG6>Q1#1
breakWhile = true; !h "6h
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pg%'_+$~m
for(int i=0;i<nStartPos.length;i++) pg.z `k
{ 7fg +WZ
if(!fileSplitterFetch.bDownOver) 8 )w75+&
{ DgQw9`WA
breakWhile = false; ARD&L$AX
break; x3JX}yCX
} c9 UJ=
} A$9^JF0$
if(breakWhile) 1~HR;cTv=
break; }LaRa.3
D6KYkN(,v
Gg3cY{7
//count++; *0 0K3
//if(count>4) ?1z." &
// siteStop(); N!fTt,
} 5+gSpg]i
3',|HA /x
$RYsqX\v
System.err.println("文件下载结束！"); CqRG !J
} V*m@Rs!)2
catch(Exception e){e.printStackTrace ();} G@O~*k1v
} ]y:ez8RFPU
q~^qf
j(`L)/|O
//获得文件长度 h7( R/Rf
public long getFileSize() )@ /!B`
{ i5>]$j1/
int nFileLength = -1; F|3 =Cl
try{ O+Zt*jN;
URL url = new URL(siteInfoBean.getSSiteURL()); 39w|2%(O.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GJLlMi
httpConnection.setRequestProperty("User-Agent","NetFox"); _IA@X. )?
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`(r[BV|h}
int responseCode=httpConnection.getResponseCode(); [_&\wHX
if(responseCode>=400) )PRyDC-
{ c teUKK.|)
processErrorCode(responseCode); f\ wP}c'
return -2; //-2 represent access is error d{UyiZm\
} .."=
D=w5Lks
RN0@Q~oTI
String sHeader; @c<*l+Qc
)>]~Y
?(&)p~o
for(int i=1;;i++) /5ngPHy&
{ bN6FhKg|
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); cI9}YSk
//Utility.log(in.readLine()); +[MzF EE[
sHeader=httpConnection.getHeaderFieldKey(i); <mm.b
if(sHeader!=null) Jv*(DFt!v
{ ?]`kc
if(sHeader.equals("Content-Length")) GgoPwl#{
{ a)+;<GZ~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); H0zKL]D'>
break; 1]L 0r
} C0xjM0
} io[$QTY
else iUv#oX H
break; rKR2v(c
} !+;'kI2
} X\r?g
catch(IOException e){e.printStackTrace ();} nMK,g>wp
catch(Exception e){e.printStackTrace ();} HMQi:s7%
Hoaf3 `n
TNA?fm
Utility.log(nFileLength); 1rr\l`
f\W1u#;u)
(RP"VEVR
return nFileLength; B?qLXRv
} Jl-Lz03YG
Pa.D+
}{J5)\s9
//保存下载信息（文件指针位置） l .8@F
private void write_nPos() zFy0SzF
{ wzr3y}fCe
try{ v-;j44sB
output = new DataOutputStream(new FileOutputStream(tmpFile)); p#VA-RSUQ|
output.writeInt(nStartPos.length); vI<n~FHt
for(int i=0;i<nStartPos.length;i++) >a@c5
{ S}q6CG7 u
// output.writeLong(nPos); ^Z:oCTOP
output.writeLong(fileSplitterFetch.nStartPos); W0]W[b,:u$
output.writeLong(fileSplitterFetch.nEndPos); 2]Nc@wX`p
} CS;bm`8a
output.close(); f$G{7%9*
} jl;%?bx
catch(IOException e){e.printStackTrace ();} iRo/~(
catch(Exception e){e.printStackTrace ();} '!)|;qe
} Jww LAQ5
[NE:$@
_S43_hW
//读取保存的下载信息（文件指针位置） 5]/i[T_
private void read_nPos() bk@F/KqL
{ <,%qt_ !
try{ W}<'Y@[,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); lg)jc3
int nCount = input.readInt(); (mHCK5
nStartPos = new long[nCount]; 481SDG[b
nEndPos = new long[nCount]; |IbCN
for(int i=0;i<nStartPos.length;i++) _5F8F4QY`
{ 0B0Uay'd_
nStartPos = input.readLong(); lx8@;9fLy
nEndPos = input.readLong(); B'( /W@
} nE!h&}(
input.close(); LTGKs^i4
} /Ulv/Thl
catch(IOException e){e.printStackTrace ();} 4ZY0!'be-R
catch(Exception e){e.printStackTrace ();} ,qF;#nB-
} :Ogt{t
#&JhA2]q
).[Mnt/Ft
private void processErrorCode(int nErrorCode) ~J}{'l1{yf
{ eyq8wQT
System.err.println("Error Code : " + nErrorCode); W7k\j&x
} 1+1Z]!nG#!
"0JG96&\
%F'*0<
//停止文件下载 7^}np^[HB
public void siteStop() 2f'3Vjp~G
{ P4xQ:$2!
bStop = true; ? Xb8B5
for(int i=0;i<nStartPos.length;i++) r=Up-(j
fileSplitterFetch.splitterStop(); PNwXZ/N%
-e6~0%X
N/ 7Q(^
} E1(2wJ-3"
} 2!Ip!IQ:
//负责部分文件的抓取 ZJCD)?]=3
**FileSplitterFetch.java C-Q]f
*/ >7yOu!l
package NetFox; YGRv``(
D^+#RR'#,
!a"RHg:HO
import java.io.*; 0^l|W|.Z
import java.net.*; Tx)X\&ij&
%d<uOCf\Q
u{F^Ngy )
public class FileSplitterFetch extends Thread { o"5Bg%H
\`:X37n)0q
1'qllkT
String sURL; //File URL 1&S34wJF
long nStartPos; //File Snippet Start Position 95Q{d'&
long nEndPos; //File Snippet End Position `Zn2Vx
int nThreadID; //Thread's ID g`6_Ao8
boolean bDownOver = false; //Downing is over $3aq+w:
boolean bStop = false; //Stop identical ^T):\x(
FileAccessI fileAccessI = null; //File Access interface Y|eB;Dm1q
jSLNQ
CAGaZ rx
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .G"UM>.}d
{ H-&Z+4 +Xs
this.sURL = sURL; f9A^0A?c
this.nStartPos = nStart; V2< 4~J2:9
this.nEndPos = nEnd; m_{?py@tZ
nThreadID = id; . zM
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6$"gm$3O]
} o)_;cCr)q
?LP&VU1
K!|%mI8gk
public void run() wB(A['k
{ K8,fw-S%
while(nStartPos < nEndPos && !bStop) eK%~`Y
{ 9cJzL"yi
]s3U+t?
u="VJ3
try{ 9EryHV|
URL url = new URL(sURL); eGZ{%\PH<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FX+;azE7
httpConnection.setRequestProperty("User-Agent","NetFox"); Tvd=EO
String sProperty = "bytes="+nStartPos+"-"; p&Usl.
httpConnection.setRequestProperty("RANGE",sProperty); qPJU}(9#B
Utility.log(sProperty); SiN22k+
QfI=
8mM^wT
InputStream input = httpConnection.getInputStream(); JGS4r+
//logResponseHead(httpConnection); mlolSD;7
lM1Y }
v!oXcHK/
byte[] b = new byte[1024]; Dps0$fc
int nRead; J1,\Q<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) M" |Mte
{ B+yr 6Q.
nStartPos += fileAccessI.write(b,0,nRead); 577H{;pW
//if(nThreadID == 1) /ESmQc:DWB
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yFp8 >
} <"|BuK
~HbZRDcJc
B(<;]
Utility.log("Thread " + nThreadID + " is over!"); ekB!d
bDownOver = true; >P7|-bV
//nPos = fileAccessI.write (b,0,nRead); /IDfGAE
} dpHK~n j\_
catch(Exception e){e.printStackTrace ();} W~ 6ii\
} MV"aO@
} lNtZd?=>
]AlRu(
a8K"Z-LlQ
//打印回应的头信息 bAIo5lr
public void logResponseHead(HttpURLConnection con) +" 4E:9P?
{ GT|=Kx$;
for(int i=1;;i++) !oTF2Q+C
{ 9p ;)s
String header=con.getHeaderFieldKey(i); S^}@X?v
if(header!=null) $<jI<vD+:
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :-xF=Y(;
Utility.log(header+" : "+con.getHeaderField(header)); S<Zb>9pl
else ]|cL+|':y
break; !(=bH"P
} b[<Q_7~2
} v#EXlpS
=i jGB~
r"s <;
public void splitterStop() P$MAURFm
{ Yrb[:;Y
bStop = true; a=LjFpv/]
} rYI9?q
^:Vwblv(
tWkD@w`Lnn
} $E;`Y|r%WK
qV57P6<
V!=1 !"}OG
/* AhOvI{
**FileAccess.java rSU%!E+|<
*//文件访问(定位，写) ;qT~81
package NetFox; KD]8n]c
import java.io.*; %a-:f)@
Jq1 Zb
m09 Bds
public class FileAccessI implements Serializable{ {b4+ Yc
(dO, +~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 bg$df 0
RandomAccessFile oSavedFile; `.PZx%=
long nPos; ax7]>Z=%d"
N~H9|CX
r0=Aru5n
public FileAccessI() throws IOException T9enyYt%
{ "T4Z#t
this("",0); S5RQ
} E7E>w#T5
|ToCRM
W2Y%PD9a
public FileAccessI(String sName,long nPos) throws IOException :~JgB
{ e6{}hiM
oSavedFile = new RandomAccessFile(sName,"rw"); 1X\dH<B}
this.nPos = nPos; 6yZfV7I
oSavedFile.seek(nPos); Cg NfqT0
} [bH5UTA
%h;~@-$
Bfw]#"N`
public synchronized int write(byte[] b,int nStart,int nLen) =8`,,=P^
{ *RKYdwnb
int n = -1; A-:58Qau+
try{ ZgCG'SU
oSavedFile.write(b,nStart,nLen); $Oa}U3
n = nLen; k?|l;6
} z38&7+
catch(IOException e) (7w`BR9B
{ fk%r?K6K
e.printStackTrace (); ]Auk5M+
} 7_>No*[
(JS1}T
X)iQ){21V
return n; mx s=<
} |eIEqq.Eb
:AYp{"{
ffo{4er
} =\7o@ 38
qYj EQz
X-Y:)UT
/* 0sW=;R2
**SiteInfoBean.java OgjSyzc
*/ H3T4v1o6
package NetFox; N(0G!sTI
gE^ {@^
g1-^@&q
public class SiteInfoBean { \4y7!
9(k5Irv"'h
HJT}v/FZ
private String sSiteURL; //Site's URL >YuBi:z
private String sFilePath; //Saved File's Path 0?525^
private String sFileName; //Saved File's Name :Rc>=)<7
private int nSplitter; //Count of Splited Downloading File E[bJ5o**#
k4te[6)
L 1=HD
public SiteInfoBean() E/9h"zowS
{//nSplitter的缺省值为5 ,a&N1G.
//default value of nSplitter is 5 zg,?aAm
this("","","",5); ej dYh $
} }6SfI;
f Co-ony
Ht,_<zP;
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) qh;ahX~
{ 4PUSFZK?
sSiteURL= sURL; w[@>k@=
sFilePath = sPath; 7!Z\B-_,
sFileName = sName; -MZLkSU
this.nSplitter = nSpiltter; 6tXx--Nh
jt-Cy
%(h-cuhq
} }MAvEaUd
a]^hcKo4
K@lZuQ.1
public String getSSiteURL() s"b()JP
{ Z_{`$nW
return sSiteURL; 1qXqQA
} lquY_lrri
+9db1:
FWqnlK#
public void setSSiteURL(String value) 7g1"s1~or
{ cwiHHf>
sSiteURL = value; &!uw;|%
} Htn'(Q
'6Dt@^-PZ
N|pjGgI
public String getSFilePath() S\2QZ[u
{ txM R[o_
return sFilePath; sU"D%G
} %''z~LzJ8
rug^_d=B
dj,7lJy
public void setSFilePath(String value) o, e y.
{ (u`[I4z`
sFilePath = value; %/!n]g-
} hXr`S4aJ
e6n1/TtqM
~_v?M%5i
public String getSFileName() |&vQ1o|}
{ -#srn1A>
return sFileName; [V'3/#Z
} tpw0j CVu
&>kklP
a86m?)-c
public void setSFileName(String value) FtbqZN[
{ \,jrug<C$^
sFileName = value; Qzy[
} T;D`=p#
$P#Cf&R
Wlm%W>%
public int getNSplitter() k{>rI2;
{ F?=(4Pyvu
return nSplitter; UBoN}iR
} $r%m<Uc;}O
'~i;g.n=}-
Zj;2>
public void setNSplitter(int nCount) MIo5Y`T
{ IgH[xwzy[
nSplitter = nCount; It,m %5 Py
} Ql8E9~h
} Qp8.D4^@3
bZ c&uq_
sXm8KV
/* -FA]%Pl<'
**Utility.java M,1Yce%+}
*/ ])paU8u
package NetFox; Am3^3>
Iw(2D(se
#W`>vd}
public class Utility { !Irmc*;QE
LQ4GQqS*
jSbO1go#
public Utility() pVe@HJy6G
{ pjr,X+6o
yP2[!vYw
%m[ :},
} J0xOB;rd
SpbOvY=>
//线程睡眠 N\b%+vR
public static void sleep(int nSecond) [AE-~+m)^
{ "<b~pfCOQk
try{ F*QZVg+<*X
Thread.sleep(nSecond); sOA!Sl
} I=)Hb?qT~
catch(Exception e) l< 8RG@
{ lV!ecJw$
e.printStackTrace (); WHxq-&=
} /zZ$<mVG
} kOR5'rh
'T@K$xL8
//日志 t{t*.{w
public static void log(String sMsg) B6r~4=w_
{ ! 7,rz1s73
System.err.println(sMsg); Th,15H DA
} v P8.{$
e|Iylv[3
`-!t8BH
public static void log(int sMsg) F`,XB[}2
{ 'c[4-m3bg
System.err.println(sMsg); l +RT>jAmK
} J<dr x_gc
} -+4:} sD
D-*`b&i48
S8;Dk@rr(y
/* ")kE1D%
**TestMethod.java clK3kBh~&
*/ `oN~
package NetFox; w^tNYN,i
lC&U9=7W
$/;:Xb=q
public class TestMethod { g[fCvWm#d
@f442@_4
f h05*]r
public TestMethod() IT& U%hw
{ ///xx/weblogic60b2_win.exe ^sIxR*C[v
try{ {M:Fsay>p
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); cl4`FU
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); QCkPua9
SiteFileFetch fileFetch = new SiteFileFetch(bean); [?uiM^&
fileFetch.start(); ,Zs:e.
} GKdQ
catch(Exception e){e.printStackTrace ();} OI;0dS
1zNH[
# JHicx\8l
} zOA{S~>
dUn+?
WCxt-+#
public static void main(String[] args) oLVy?M%{P
{ kzPHPERA]
new TestMethod(); ~M`-sSjZs
} 1<a+91*=e
} 8_0j^oh
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