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)); "TLY:V
} n#NE.ap$&,
for(int i=0;i<nEndPos.length-1;i++) SWrt4G
{ ,X&(BQj h
nEndPos = nStartPos[i+1]; .y)Y20=o!
} XDot3)2`
nEndPos[nEndPos.length-1] = nFileLength; "!fvEE
} Qd{h3K^hlu
} A#WvN>
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bnm3 cR:h"
//启动子线程 miq"3
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; gvoo1 Sa
for(int i=0;i<nStartPos.length;i++) ;&A%"8o
{ kOQq+_Y
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "F$0NYb]I
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), WgV'T#*
nStartPos,nEndPos,i); ftw@nQNU
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #?V7kds]
fileSplitterFetch.start(); `H^?jX>7
} -kv'C6gB
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Me.t_)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Xv5|j/<~p
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _LOV&83O(
nEndPos = " + nFileLength); bR0z$~
// fileSplitterFetch[nPos.length-1].start(); R3[H#*gF<
AzfYw'^&9
Mzbbr57n
//等待子线程结束 B <CK~ybY
//int count = 0; WX2w7O'R
//是否结束while循环 J[?7`6\M
boolean breakWhile = false; u`Sg'ro
z.xOT;t
UImd*;2TE
while(!bStop) HgY#O r(
{ _F"o0K!u
write_nPos(); 'u%;5;%2
Utility.sleep(500); <f')]
breakWhile = true; ]t23qA@^2
2&k5X-Y
~I_v {
for(int i=0;i<nStartPos.length;i++) _i-(`5
{ DM73 Nn^5
if(!fileSplitterFetch.bDownOver) Z6`oGFq
{ n*HRGJ
breakWhile = false; .QaHE`e{
break; gk*Md+
} DH5]Kzb/
} m V U(b,
if(breakWhile) us:V\V
break; jW?siQO^
L'*P;z7<
l$:.bwXXO
//count++; h /.^iT
//if(count>4) B!#F!Wk"
// siteStop(); X`,]@c%C`
} Ga%x(1U[&
,z*-93H1
Gz>M`M`[4
System.err.println("文件下载结束！"); ]Q%|69H}B
} syseYt]
catch(Exception e){e.printStackTrace ();} Yy_o*Ozq
} z@_9.n]
6*cY[R|q!
@eQo
//获得文件长度 w'Cn3b)`
public long getFileSize() RCS91[
{ f a9n6uT
int nFileLength = -1; cITF=Ez
try{ :EXH8n&|
URL url = new URL(siteInfoBean.getSSiteURL()); N~w4|q!]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mJ>@Dh3>G
httpConnection.setRequestProperty("User-Agent","NetFox"); bhIyq4N
r%QnV0L^
U;QN+fF]u
int responseCode=httpConnection.getResponseCode(); #kuk3}&
if(responseCode>=400) <MPoDf?h
{ )bM #s">Y
processErrorCode(responseCode); @rTAbEk{U
return -2; //-2 represent access is error @\!9dK-W
} icX$<lD
6L2Si4OGjG
vfh0aW-O
String sHeader; \[-z4Fxg|'
LEUD6 M+~t
kRyt|ryWh
for(int i=1;;i++) >-~2:d\M3
{ 0B4&!J
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); q$;'Fy%oy
//Utility.log(in.readLine()); CkJU5D
sHeader=httpConnection.getHeaderFieldKey(i); xSQ0]vE
if(sHeader!=null) q0}?F
{ /eoS$q
if(sHeader.equals("Content-Length")) D-/aS5wM
{ OfR\8hAY
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ""dX4^gtU
break; ~+y0UEtq7
} /!r#=enG7
} Vs)%*1><
else UacGq,
break; ATeXOe
} W[dMf!(
} `mI%Se
catch(IOException e){e.printStackTrace ();} n(mS
catch(Exception e){e.printStackTrace ();} }> 51oBgk_
e<wRA["
0P5!fXs*
Utility.log(nFileLength); 9}4EW4
.?TPoqs7Z
"dKYJ&$
return nFileLength; $J~~.PUXQ
} +Oae3VFf;
"!yKX(aTX
9"@P.8_
//保存下载信息（文件指针位置） jJpSn[{
private void write_nPos() r "^{?0
{ %HRFH
try{ >PsP y.
output = new DataOutputStream(new FileOutputStream(tmpFile)); a?+Ni|+
output.writeInt(nStartPos.length); !f(aWrw7e6
for(int i=0;i<nStartPos.length;i++) S;o U'KOY
{ )$#r6fQO
// output.writeLong(nPos); dh7PpuN{
output.writeLong(fileSplitterFetch.nStartPos); !U,^+"l'GP
output.writeLong(fileSplitterFetch.nEndPos); -jZP&8dPH
} /nK)esB1L
output.close(); bw@DcT&,
} S=Ihg
catch(IOException e){e.printStackTrace ();} @~!1wPvF`I
catch(Exception e){e.printStackTrace ();} 5-277?
} seFug
5(/ 5$u
+ *YGsM`E9
//读取保存的下载信息（文件指针位置） BO5gwvyI
private void read_nPos() @-z#vJ5Qe{
{ AUloP?24
try{ 728}K^7:
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); iA~b[20&
int nCount = input.readInt(); imx/hz!
nStartPos = new long[nCount]; u_aln[oIv
nEndPos = new long[nCount]; 8ycmvpJ
for(int i=0;i<nStartPos.length;i++) )shzJ9G
{ O<R6^0B42
nStartPos = input.readLong(); xM1>kbo|
nEndPos = input.readLong(); LzEAA{
} lu^c^p;
input.close(); {&Kq/sRz
} dqMR<Nl&
catch(IOException e){e.printStackTrace ();} q8:Z.<%8
catch(Exception e){e.printStackTrace ();} (K$K;f$"r
} GHHErXT\a
J&{qe@^
WgdL^PN(h
private void processErrorCode(int nErrorCode) ?VMj;+'tr
{ U~8.uldnF
System.err.println("Error Code : " + nErrorCode); XpzdvR1
} w;.'>ORC
&jgpeFiiC
]P TTI\n
//停止文件下载 PN{l)&K2.
public void siteStop() '3>kDH+
{ 1#AdEd[
bStop = true; j+3~
for(int i=0;i<nStartPos.length;i++) _nR8L`l*z
fileSplitterFetch.splitterStop(); TEZ^Ia
khl(9R4a
/Yk2 |L
} :&=TE2
} L~1u?-zu
//负责部分文件的抓取 &* 4uji
**FileSplitterFetch.java 3G9YpA_}X
*/ b#-5b%ON
package NetFox; dbkccO}WB
%3e}YQe)
e~r%8.Wm
import java.io.*; 5_+vjV;5
import java.net.*; Xj^6ZJc
G7k0P-r,0
UA[2R1}d
public class FileSplitterFetch extends Thread { #q~SfG
1<]g7W
N2_j[Pe
String sURL; //File URL (NUk{MTX
long nStartPos; //File Snippet Start Position >n@?F[Y
long nEndPos; //File Snippet End Position oK h#th
int nThreadID; //Thread's ID ;T2)nSAqt
boolean bDownOver = false; //Downing is over wTFM:N
boolean bStop = false; //Stop identical lgZ3=h
FileAccessI fileAccessI = null; //File Access interface )5lo^Qb
Lj"~6l`)
xm>RLx}9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException uROt h_/
{ tRYMK+
this.sURL = sURL; oC>QJ(o,8
this.nStartPos = nStart; =:aH2T*
this.nEndPos = nEnd; <@n/[ +3
nThreadID = id; Q3#-q>;7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 lTPo2-j/eK
} 88}c+V+N!
: j&M&+
KO(+%>^R
public void run() }N5>^y
{ 4NL TtK
while(nStartPos < nEndPos && !bStop) 59";{"sw
{ -zg,pK$+
SU"-%}~O#,
CGIcuHp
try{ [7?K9r\#
URL url = new URL(sURL); KyW6[WA9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3%m2$\
httpConnection.setRequestProperty("User-Agent","NetFox"); ykSn=0
String sProperty = "bytes="+nStartPos+"-"; !v|j C
httpConnection.setRequestProperty("RANGE",sProperty); /-<S FT`
Utility.log(sProperty); 9|T%q2O
nMD^x
:W,6zv(..u
InputStream input = httpConnection.getInputStream(); M#on-[
//logResponseHead(httpConnection); {*H&NI
Pze$QBNoRd
^Sx0t
byte[] b = new byte[1024]; CU 2;m\Hc
int nRead; %'j)~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6\)61o_1|
{ zF%CFqQ
nStartPos += fileAccessI.write(b,0,nRead); c&2ZjM
//if(nThreadID == 1) /Dj6Bj }
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T[s_w-<7$
} @(PYeXdV6&
^jb55X}
7/NXb
Utility.log("Thread " + nThreadID + " is over!"); [P2$[|IM
bDownOver = true; Lm\N`
//nPos = fileAccessI.write (b,0,nRead); W-@A
} T%K(opISc(
catch(Exception e){e.printStackTrace ();} XJsHy_6
} i$)bZr\
} =,KRZqz
&TE=$a:d&
9 )u*IGj
//打印回应的头信息 7*y_~H
public void logResponseHead(HttpURLConnection con) J&S$F:HM
{ O>xGH0H
for(int i=1;;i++) .&.j?kb
{ =6imrRaaV
String header=con.getHeaderFieldKey(i); $x 6Rmd{
if(header!=null) [o<R#f`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /j./
Utility.log(header+" : "+con.getHeaderField(header)); :kqJ~
else Dna0M0
break; $"C]y$}
} 0 V*Di2
} r#*kx#"
oabc=N!7r
R9D<lX0%
public void splitterStop() JPS22i)P
{ q5?g/-_0[
bStop = true; %TdZ_
} MVz=:2)J2
MhNzmI&`
ws Lg6
} U.hV1
NY\q
<Bb$d@c
/* V(1Ldl'a
**FileAccess.java U 9TEC)
*//文件访问(定位，写) Lv+lLK
package NetFox; BKfcK>%g
import java.io.*; |E0>-\6
gxpR#/(E~
r]Bwp i%
public class FileAccessI implements Serializable{ _KC)f'Cx
eX7Ev'(H
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 jI(~\`
RandomAccessFile oSavedFile; r9'lFj
long nPos; <i"U%Ds(
V"(S<o
$q]((@i.
public FileAccessI() throws IOException {MU>5\
{ .2/(G{}U
this("",0); : m$cnq~h
} X|t?{.p
h<\o[n7j
A:ls'MkZ4
public FileAccessI(String sName,long nPos) throws IOException `o yz"07m
{ aM5zYj`pW
oSavedFile = new RandomAccessFile(sName,"rw"); ~PP*k QZlJ
this.nPos = nPos; T{d7,.:
oSavedFile.seek(nPos); $-YS\R\9x
} +Sv`23G@
!OekN,6
TAlpy$
public synchronized int write(byte[] b,int nStart,int nLen) &K2[>5 mG
{ } WY7!Y
int n = -1; #K'3`dpL
try{ p>h B&h
oSavedFile.write(b,nStart,nLen); 2<)63[YO
n = nLen; Fh9`8
} .,(bDXl?
catch(IOException e) e4u$+
{ qCOv4b`
e.printStackTrace (); >/nS<y>
} VS@o_fUx)
kX."|]
E8J`7sa
return n; "12.Bi.O"[
} @4Z>;
$Ll]h</Z
e5maZ(.;F
} ,,S5 8\x
'W usEME
sh[Yu
/* \Xc6K!HJM
**SiteInfoBean.java FYR%>Em
*/ ~{iBm"4
package NetFox; EMzJJe{Cv
p8hF`D~
%YG ~ql
public class SiteInfoBean { eG9tn{
]S<eO6z
[5,aBf)X
private String sSiteURL; //Site's URL > xkl7D
private String sFilePath; //Saved File's Path ^%-$8sV
private String sFileName; //Saved File's Name 5t#+UR
private int nSplitter; //Count of Splited Downloading File su/l'p'
)Y}t~ Zfx
Gp'rN}i^
public SiteInfoBean() :,%~rR
{//nSplitter的缺省值为5 st P~/}
//default value of nSplitter is 5 csz/[*
this("","","",5); HGfV2FtTz
} >'wl)j$
eWS[|'dl
KhAj`vOzK
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) J?Brnf.
{ /c'3I
sSiteURL= sURL; 7)!(0.&
sFilePath = sPath; h2ewYe<87`
sFileName = sName; Z0g3> iItM
this.nSplitter = nSpiltter; ]N_(M
f1(V~{N,+
c<L^ 1,G2
} v~e@:7d i
j*nZ
8PB(<|}u
public String getSSiteURL() _'0HkT{I
{ r-v;A
return sSiteURL; >J^bs &j
} 0? (
WM5s
Wk"4mq
public void setSSiteURL(String value) V|KYkEl r1
{ '; ,DgR;'
sSiteURL = value; ne] |\]
} n3t1'_/TU}
h 1G`z
$'*@g1vY
public String getSFilePath() i<&*f}='
{ iM+K&\{_h
return sFilePath; fu'iG7U M
} %l%5Q;t
Y,?s-AB
Ks.m5R
public void setSFilePath(String value) u"XqWLTV
{ xr+K: bw
sFilePath = value; |F[E h ~
} Vd~{SS2>
Hq[d!qc
]J+}WR
public String getSFileName() YMOy6C
{ #-dfG.*
return sFileName; #\KSv Z
} Q*}#?g
P1)f-:;
EKoAIC*?p
public void setSFileName(String value) ac"Pn? q
{ VXXo\LQUU
sFileName = value; pV{MW#e
} %5V!Fdb
['ol]ZJ
Wm$(b2t
public int getNSplitter() N|K,{ p^li
{ Q1J./C}
return nSplitter; eWzD'3h^
} H7n5k,
eKi/Mt
Fj}|uiOQUS
public void setNSplitter(int nCount) i*B@#;;F
{ r2H \B,_
nSplitter = nCount; &SfJwdG*=
} {$z)7s
} < .&t'W
:W(3<D7\
2-5AKm@K
/* fH~InDT^
**Utility.java 3&'ll51t
*/ lG12Su/
package NetFox; 7|LJwXQ-
qawb9Iud0
T-ID{i
public class Utility { ^_ <jg0V
qYv/" 1
*5Upb,**
public Utility() x'kwk
{ N p9N#m?
>FED*C4
?#?[6t
} ks|[`FH
J.Mj76\_
//线程睡眠 834(kw+#9
public static void sleep(int nSecond) T)wc{C9w
{ m<)0XE6w
try{ Z&FC:4!!
Thread.sleep(nSecond); (,1}P
} b:3n)-V{u
catch(Exception e) 08AC9
{ {Ts@#V=:
e.printStackTrace (); N<o3pX2i]
} hFl$u8KV
} U]j4Izq
su6x okt
//日志 f"t\-ux.b
public static void log(String sMsg) {o"X8
{ IPmSkK
System.err.println(sMsg); C{>@b:]p
} It'hmwu#
nB"r<?n<
]jiM
public static void log(int sMsg) jqxeON
{ nM:e<`r
System.err.println(sMsg); p'UYHt
} {N1Ss|6
} wuE]ju<
fy04/_,q
,ButNBv
/* e^kccz2f
**TestMethod.java 4DI.RK9
*/ RG/M-
package NetFox; <,p|3p3
*O-1zIlp
bOjvrg;Sz\
public class TestMethod { Poy ]5:.
o`S|
UwOZBF<
public TestMethod() .,zrr&Po
{ ///xx/weblogic60b2_win.exe yoa"21E$
try{ xLX<.z!r
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 58\rl G
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *(6vO{
SiteFileFetch fileFetch = new SiteFileFetch(bean); wY|&qX,
fileFetch.start(); W^; wr#
} -=BQVJ_dK{
catch(Exception e){e.printStackTrace ();} .Tr!/mf_
]oB-qfbH
5=%:CN!/@p
} hJY= )
ceBu i8a |
/Am,5X.
public static void main(String[] args) `|K30hRp:
{ 9bvzt8pc
new TestMethod(); #<df!)
} {^>dQ+Sx7
} C9zQ{G
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