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)); Aa0b6?Jm
} &cWjEx
for(int i=0;i<nEndPos.length-1;i++) Z/x*Y#0@n
{ b`yZ|j'ikd
nEndPos = nStartPos[i+1]; '7wd$rl
} |Fm6#1A@
nEndPos[nEndPos.length-1] = nFileLength; bNFLO Q
} YprHwL
} Pq*s{
dY?`f<*
ES~^M840f
//启动子线程 H>9CW<8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b|Q)[y]
for(int i=0;i<nStartPos.length;i++) b" xmqWa
{ du$|lxC
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Mb3}7@/[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |qZko[W}=
nStartPos,nEndPos,i); (b?{xf'G
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Go,N>HN
fileSplitterFetch.start(); u2oKH{/z
} Qk!;M|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PH"hn]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,+`61J3W
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #;n+YM">:
nEndPos = " + nFileLength); M"%Q&o/I
// fileSplitterFetch[nPos.length-1].start(); ]yjl~3
`1{N=!U(&
%WqNiF0-
//等待子线程结束 UAR5^
//int count = 0; H|cNH=
//是否结束while循环 Dnc(l(
boolean breakWhile = false; $+.l*]
1&fc1uYB4
dU\%Cq-G)
while(!bStop) l5l>d62
{ UhIDRR
write_nPos(); \!]Ua.e<
Utility.sleep(500); #:T-hRu
breakWhile = true; ,=?{("+
cA6lge<{~
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for(int i=0;i<nStartPos.length;i++) eIl]oC7*
{ As+t##gN
if(!fileSplitterFetch.bDownOver) T~h5B(J;
{ jxJv.
breakWhile = false; WyP W*
break; CK, 6ytB
} eNiaM6(J
} -W,}rcj*|
if(breakWhile) 2lL,zFAq
break; oD}uOC}FS{
'zh7_%
bQ|V!mrN}
//count++; DcSnia62f
//if(count>4) <0S=,!
// siteStop(); pm{|?R
} V.wqZ {G
m7T)m0
tGB@$UmfU
System.err.println("文件下载结束！"); :!zl^J;
} dg4vc][
catch(Exception e){e.printStackTrace ();} +l=r#JF
} R *F l8
Zw wqSyuGf
@29U@T
//获得文件长度 !bV5Sr^
public long getFileSize() d;n."+=[x
{ Pz$R(TV
int nFileLength = -1; Nan[<
try{ TIvRhbu
URL url = new URL(siteInfoBean.getSSiteURL()); v9T_&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H4]Ul eU
httpConnection.setRequestProperty("User-Agent","NetFox"); soCi[j$lH
]~Y<o
u+{a8=
int responseCode=httpConnection.getResponseCode(); epgPT'^
if(responseCode>=400) ^_lzZOhG
{ KN-avu_Ix
processErrorCode(responseCode); 5Enotp[
return -2; //-2 represent access is error ``E/m<r:$
} ^U]UqX`
.KdyJ6o
q{+_ <2U|
String sHeader; LY+|[qka
zRPeNdX
c&L"N!4z
for(int i=1;;i++) Ao/ jt<
{ *}8t{ F@k
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); r[K5w
//Utility.log(in.readLine()); 8mQmi`
sHeader=httpConnection.getHeaderFieldKey(i); N<DGw?Rl
if(sHeader!=null) +>4;Zd!@d
{ jMpD+Mb
if(sHeader.equals("Content-Length")) &?h,7 D;A
{ WVLHfkN
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;`6^6p\p
break; VcoOeAKL
} U)3DQ6T99
} RVeEkv[qp
else ;D$)P7k6
break; @]ao"ui@/
} IUwm}9Q!
} <mAhr
catch(IOException e){e.printStackTrace ();} yBI'djL~>
catch(Exception e){e.printStackTrace ();} MR}Agu#LG
JY6 Qp
Q~T$N
Utility.log(nFileLength); )&!&AlLn
nMJ#<'v^!2
;amXY@RmH
return nFileLength; )wNP( @$L
} aE2.L;Tk?
&-;5* lg)0
oJfr +3I
//保存下载信息（文件指针位置） 73){K?R
private void write_nPos() [Jv@J\
{ h*v8#\b$J_
try{ L`24?Y{
output = new DataOutputStream(new FileOutputStream(tmpFile)); 6:~v4W!k
output.writeInt(nStartPos.length); o]opdw
for(int i=0;i<nStartPos.length;i++) IC7M$
{ h2D>;k
// output.writeLong(nPos); uS^Ipxe\
output.writeLong(fileSplitterFetch.nStartPos); /3{b%0Aa
output.writeLong(fileSplitterFetch.nEndPos); s)pbS}L
} hodgDrmO/
output.close(); vuYSVI2=H
} )-._FOZ6
catch(IOException e){e.printStackTrace ();} 1@-Ns
catch(Exception e){e.printStackTrace ();} ' <=+;q
} VTH> o>g
pfI"36]F
sQ\8>[]
//读取保存的下载信息（文件指针位置） q7E~+p(>(
private void read_nPos() gdQvp=v]
{ c??mL4$'N
try{ S.f5v8
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &oX>*6L
int nCount = input.readInt(); O`<KwUx !
nStartPos = new long[nCount]; (}2~<
nEndPos = new long[nCount]; pS7w' H
for(int i=0;i<nStartPos.length;i++) sL$:"=
{ \:UIc*S
nStartPos = input.readLong(); a5TioQ
nEndPos = input.readLong(); ~ (jKz}'~U
} n~V ]Z
input.close(); b"{'T]"*j
} :Cj OPl
catch(IOException e){e.printStackTrace ();} &*aIEa^
catch(Exception e){e.printStackTrace ();} ;67x0)kn
} ]'=)2 .}
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Sxh]R+Xb
private void processErrorCode(int nErrorCode) 71t*%
{ ~o~!+`@q
System.err.println("Error Code : " + nErrorCode); TJR:vr
} L bmawi^
TtTj28k7
lE(a%'36
//停止文件下载 ][p>Y>:b-
public void siteStop() $cU!m(SILQ
{ 5lUF7:A>#
bStop = true; !*B'?|a<\
for(int i=0;i<nStartPos.length;i++) gq'Y!BBQy
fileSplitterFetch.splitterStop(); /^#;d UB
kZGRxp9
>]vlkA(
} -^hWM}F
} f@|A[>"V
//负责部分文件的抓取 LoN< oj5
**FileSplitterFetch.java =V-|#j
*/ x#xFh0CA
package NetFox; HOJs[mqB%
naR0@Q"\h
IS&ZqE(`e
import java.io.*; 3@$,s~+ 3
import java.net.*; 9CWezI+
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,NyY>~+
public class FileSplitterFetch extends Thread { E^/t$M|H
@] DVD
|es?;s'
String sURL; //File URL 3 09hn
long nStartPos; //File Snippet Start Position TE7nJ gm
long nEndPos; //File Snippet End Position SBfT20z[
int nThreadID; //Thread's ID ?kH8Lw~{5W
boolean bDownOver = false; //Downing is over -~v2BN/
boolean bStop = false; //Stop identical 1q:2\d]
FileAccessI fileAccessI = null; //File Access interface ][+#;avU
g+Sbl
W_\5nF
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;RC{<wBTx
{ xy/`ZS2WPq
this.sURL = sURL; QSdHm
this.nStartPos = nStart; 8"2=U6*C
this.nEndPos = nEnd; CUBEW~X}M
nThreadID = id; i]YV {
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p'*>vk
} pz\ +U7
mGJKvJF
ORHp$Un~)
public void run() i@)i$i4
{ "/3'XOK|
while(nStartPos < nEndPos && !bStop) [65`$x-
{ P2BWuhF
`1$@|FgyC
1PQ~jfGi
try{ k;AD`7(=
URL url = new URL(sURL); V3Q+s8OIF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c[wla<dO*
httpConnection.setRequestProperty("User-Agent","NetFox"); Z'`gJ&6n
String sProperty = "bytes="+nStartPos+"-"; r~jm`y
httpConnection.setRequestProperty("RANGE",sProperty); hV8[@&Sx3
Utility.log(sProperty); 4sF"6+%5d
1PVtxL?1P
p*4':TFuD;
InputStream input = httpConnection.getInputStream(); .h@rLorm>
//logResponseHead(httpConnection); GP!?^r:en
n'wU;!W9
V:In>u$QJ!
byte[] b = new byte[1024]; Bu<M\w?7Y
int nRead; @5=oeOg36
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "pi=$/RD9
{ Z0x ar]4V
nStartPos += fileAccessI.write(b,0,nRead); bv]`!g: C
//if(nThreadID == 1) z1PBMSG
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X@+{5%
} 8Wrh]egu1
bhTb[r
H[s(e56z
Utility.log("Thread " + nThreadID + " is over!"); y I HXg#
bDownOver = true; fxgPhnaC>
//nPos = fileAccessI.write (b,0,nRead); p `8s
} m,*QP*
catch(Exception e){e.printStackTrace ();} #|Y5,a,{
} /\ y?Y
} tvkb~
9_L[w\P|4
*xx'@e|<;
//打印回应的头信息 1tEgl\u\
public void logResponseHead(HttpURLConnection con) +X#vVD3"
{ >BR(Wd.
for(int i=1;;i++) )M,OfXa
{ ypbe!Y<i]
String header=con.getHeaderFieldKey(i); ''q@>
if(header!=null) wxR,OR
//responseHeaders.put(header,httpConnection.getHeaderField(header)); s>B5l2Q4
Utility.log(header+" : "+con.getHeaderField(header)); $:=A'd2
else Ed0QQyC@9
break; <;9I@VYK
} A_XY'z1
} N|8P)
6*PYFf`
^!<U_;+
public void splitterStop() j#X.KM
{ 6_J$UBT
bStop = true; y~Bh
} h%o%fH&F!
8qk?E6
Pj#<K%Bz
} 5QW=&zI`=
\a5U8shc
k52/w)Ro,$
/* ^`*9QjY
**FileAccess.java 3VsW@SG7N
*//文件访问(定位，写) <LmIK
package NetFox; 3p39`"~
import java.io.*; @E;=*9ek{u
1{r3#MVL
Hc! mB
public class FileAccessI implements Serializable{ na#CpS;pc
]p _L)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |*oZ_gI
RandomAccessFile oSavedFile; N^#ZJoR
long nPos; I3=%h
kY&k-K\
=@m &s^R
public FileAccessI() throws IOException {%<OD8>p
{ pf%=h |
this("",0); H(R1o~
} '[U8}z3
dq7x3v^"ZG
#Vl 0.l3
public FileAccessI(String sName,long nPos) throws IOException EqyeJq .
{ z{[xze-f
oSavedFile = new RandomAccessFile(sName,"rw"); z8jk[5z
this.nPos = nPos; 4zASMu
oSavedFile.seek(nPos); 8I-u2Y$Sr
} u}>#Eb
o4`hY/<t
B268e
public synchronized int write(byte[] b,int nStart,int nLen) vqnw#U4`
{ us;YV<)d
int n = -1; m#8m] Y
try{ CAWA3fcQp
oSavedFile.write(b,nStart,nLen); 6BY-^"W5`
n = nLen; O?NeSx1
} O#x*iI%
catch(IOException e) %u`8minCt
{ !$DIc
e.printStackTrace (); k]W[`
} 3,>0a
g3Ec"_>P
:@kGAI
return n; XOxr?NPQ^
} 4oK?-|=?
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g+DzscIT
} LG-y]4a}
kv8Fko
bsuus R9W
/* x N=i]~
**SiteInfoBean.java [r3!\HI7x
*/ P#pn*L*"T
package NetFox; ,^?^dB
7x#Ckep:I
-c(F1l
public class SiteInfoBean { ^=C{.{n
0F@"b{&0
if}-_E<F
private String sSiteURL; //Site's URL ;+0t;B!V
private String sFilePath; //Saved File's Path aki_RG>U'
private String sFileName; //Saved File's Name jL(qf~c_
private int nSplitter; //Count of Splited Downloading File >GQEqXs
H:!7:
0*%Z's\M"
public SiteInfoBean() zEs>b(5u
{//nSplitter的缺省值为5 nNrPHNfqD
//default value of nSplitter is 5 TS/.`.gT
this("","","",5); A{UULVp
} z."a.>fPaO
Fkvl%n
m6n?bEl6I
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Em?d*z
{ &Ts-a$Z7?S
sSiteURL= sURL; aD=a,
sFilePath = sPath; _Xnqb+
sFileName = sName; 3mYiQ2
this.nSplitter = nSpiltter; yMyE s8
*_R]*o!W'
n,=VQOu
} WtViW=j'
kHXL8k#T
hZh9uI7.
public String getSSiteURL() Wm_4avXtO
{ ;FBUwR}
return sSiteURL; K3m]%m2\
} uIcn{RZ_z
350_CN,
)_mr! z(S
public void setSSiteURL(String value) U"q/rcA
{ Atflf2K
sSiteURL = value; 8CnRi
} 8#(Q_
@kk4]:,w
)jkXSTZ
public String getSFilePath() yyv8gH
{ ,oaw0Vw
return sFilePath; +|bmT
} 0TN;86Mo
gN24M3{C
6:q"l\n>
public void setSFilePath(String value) xZ|Y?R5m
{ vJ\pR~?
sFilePath = value; e?_@aa9~@{
} r`AuvwHPs[
*NkA8PC
RY c!~Wh~Y
public String getSFileName() BYs-V:
{ @fs`=lL/
return sFileName; [[>wB[w
} ta`N8vnf
Y2d;E.DH8
w;k):;$
public void setSFileName(String value) xEf'Bmebk
{ tjGd )
sFileName = value; }-~X4u#
} Cl^\OZN\=
FDVcow*]n
H2 $GIY
public int getNSplitter() w"SoeU
{ R zf
return nSplitter; _Qh z3'I1
} Kw8u`$Ad7
kGd<5vCs
:4MB]v[K
public void setNSplitter(int nCount) F)s{PCl
{ AtF3%Zv2
nSplitter = nCount; deM7fN4lTi
} Mk=mT3=#
} TjHwjRa
JJ{9U(`_y6
H^.IY_I`U*
/* C?i >.t
**Utility.java Pu"R,a
*/ X{we/'>
package NetFox; U Z|HJ8_
U$ F{nZ1
:WSDf VX
public class Utility { L0&RvI#
Y`o+XimX
/9zE^YcT
public Utility() ep=qf/vd<
{ C4hx@abA
J|X 6j&-
TQ`Rk;0R
} X=Ys<TM,
vfl5Mx4
//线程睡眠 -T&.kYqnb$
public static void sleep(int nSecond) jS+AGE?5e
{ >m#e:[N
try{ K]j0_~3s
Thread.sleep(nSecond); nPs7c %
} "=6v&G]U4
catch(Exception e) -s|}Rh?Y
{ x7vctjM|
e.printStackTrace (); BWrv%7
} OvUI@,Ef
} I j$lDJS
$uap8nN
//日志 &BtK($
public static void log(String sMsg) o$[z],RO
{ +=]!P#
System.err.println(sMsg); 5w\fSY
} YKbaf(K)9
fm(e3]
KAsS[
public static void log(int sMsg) {@<J_A
{ = <j"M85.
System.err.println(sMsg); 0vVV%,v
} 6<N5_1
} m$9w"8R
M.nvB)
h.!}3\Y
/* DhX#E&
**TestMethod.java % ,N<
*/ 52.>+GC
package NetFox; }?&k a$rI
3Wwj p
CH fVQ|!\
public class TestMethod { 7T"XPV|W6
MwfOy@|N
avy"r$v_&
public TestMethod() Yp0/Ab(v
{ ///xx/weblogic60b2_win.exe xl"HotsX-x
try{ ? tfT8$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >(y<0
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); RJy=pNztm
SiteFileFetch fileFetch = new SiteFileFetch(bean); +4\U)Z/\
fileFetch.start(); O:{U^K:*
} l~D N1z6`
catch(Exception e){e.printStackTrace ();} K_ lVISBQ
A<\JQ
TRZRYm"
} L{E^?iX
0<PR+Iv*i
lpRR&
public static void main(String[] args) O$kq`'9
{ wnTV|^Q
new TestMethod(); [xh*"wT#g
} zE)~0v4
} ,*]d~Y
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