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)); &eKnLGKD
} _so\h.lt
for(int i=0;i<nEndPos.length-1;i++) w2_$>z
{ ~cQ./G4
nEndPos = nStartPos[i+1]; 4*< x0
} Y^Y|\0
nEndPos[nEndPos.length-1] = nFileLength; 2'Cwx-_G`
} u6Fm qK]Dj
} Pky/fF7e
b^_#f:_j
A^nB!veh
//启动子线程 SB0Cq
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; S\b[Bq
for(int i=0;i<nStartPos.length;i++) CtJ*:wF
{ F=!p7msRB
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rrbD0UzFA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |N/Grk4
nStartPos,nEndPos,i); WcqQR))n
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); | s%--W
fileSplitterFetch.start(); XUc(7>k
} )0UVT[7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), uP2e/a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); dU<\FW_
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", b6Pi:!4
nEndPos = " + nFileLength); wO9|_.Z{
// fileSplitterFetch[nPos.length-1].start(); ej,j1iB
FOVghq@
}vzP\
//等待子线程结束 :_V9Jwu
//int count = 0; PKFjM~J
//是否结束while循环 |fqYMhA U
boolean breakWhile = false; 6RV42r^pf
A?V}$PTlx
6U~AKq"+f
while(!bStop) E7X6Shng
{ AGu#*,K
write_nPos(); "TEF
Utility.sleep(500); ?!TFoD2'
breakWhile = true; G(gJtl
m_YXTwwx
rYez$e^r
for(int i=0;i<nStartPos.length;i++) z#9Tg"8]
{ }zC9;R(E
if(!fileSplitterFetch.bDownOver) d1]CN6 7{G
{ n'*4zxAA
breakWhile = false; 2q]y(kW+
break; )tYu3*'
} " E+V>V+
} 8*o*?1.
if(breakWhile) GPV=(}z
break; &iKy
=2v/f_
z7TMg^9#
//count++; Z 0&=Lw
//if(count>4) hK^(Y
// siteStop(); z5.Uv/n\1
} h|~I'M]*
jMUd,j`Opx
d8D028d
System.err.println("文件下载结束！"); "[h9hoN
} =T"R_3[NC
catch(Exception e){e.printStackTrace ();} cG!\P:re
} R|&jvG=|
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rSu+zS7`X
//获得文件长度 ZtHTl\z
public long getFileSize() iWu
{ ? nx3#<
int nFileLength = -1; K(jo[S
try{ k7,
URL url = new URL(siteInfoBean.getSSiteURL()); PY81MTv0;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (|O9L s7N
httpConnection.setRequestProperty("User-Agent","NetFox"); %M)LC>c
\jA#RF.W
RW"QUT
int responseCode=httpConnection.getResponseCode(); 7slpj8
if(responseCode>=400) Cp"a,%b6u
{ P=3mLz-
processErrorCode(responseCode); T.d1?
return -2; //-2 represent access is error ,f*Q3 S/I
} ZZ'5BfI"I%
lo!^h]iE!
;Aqj$ x
String sHeader; >lPWji'4;
M'gGoH}B+q
s#Ayl]8r
for(int i=1;;i++) p"@[2hK
{ f4'WT
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &|9K~#LVS
//Utility.log(in.readLine()); a gkw)#
sHeader=httpConnection.getHeaderFieldKey(i); 3uXRS,C
if(sHeader!=null) Nyx)&T&I
{ h~EGRg
if(sHeader.equals("Content-Length")) '[WVP=M<XV
{ !d.bCE~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ohU}ST:9
break; '`s+e#rs4{
} r>ziQq8C&
} X!xmto
else ^sVr#T
break; 52,[dP,g
} E.N@qMn~
} X+2uM+
catch(IOException e){e.printStackTrace ();} gwGw
catch(Exception e){e.printStackTrace ();} WuuF&0?8C
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g1kYL$o4
Utility.log(nFileLength); %T6 sm
<uG6!P
5Z@0XI
return nFileLength; }3O 0nab
} qdnwaJ;&
{gz-w|7
2A=q{7s
//保存下载信息（文件指针位置） C'7DG\pr
private void write_nPos() r'(*#
{ kqkTz_r|H
try{ Gf=3h4
output = new DataOutputStream(new FileOutputStream(tmpFile)); b(_f{R7PY
output.writeInt(nStartPos.length); x^zw1e,y
for(int i=0;i<nStartPos.length;i++) ;\g0*b(
{ @}\i`H1s
// output.writeLong(nPos); W1Vy5V|M
output.writeLong(fileSplitterFetch.nStartPos); <k?pnBI_
output.writeLong(fileSplitterFetch.nEndPos); vnN0o5
} H)k V8wU
output.close(); QHXA?nBX
} baoyU#X9
catch(IOException e){e.printStackTrace ();} Kn=0AdM
catch(Exception e){e.printStackTrace ();} 6H1;Hl f
} i!{A7mo
s(T0lul
9OYyR
//读取保存的下载信息（文件指针位置） boq=@Qh
private void read_nPos() W3zYE3DZf
{ h! Bg}B~
try{ eDsB.^|l
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9:E:3%%
int nCount = input.readInt(); xtBu]I)%
nStartPos = new long[nCount]; ?W>`skQ
nEndPos = new long[nCount]; @<.ei)cqb
for(int i=0;i<nStartPos.length;i++) L} "bp
{ u69UUkG
nStartPos = input.readLong(); {/j gB"9
nEndPos = input.readLong(); #;[0:jU0
} h/Yxm2
input.close(); kRjNz~g
} ;}Ei #T,D
catch(IOException e){e.printStackTrace ();} ",xTgB3?V
catch(Exception e){e.printStackTrace ();} f(G1xw]]@Y
} k!ID
oJZxRm[g$t
uPq@6,+
private void processErrorCode(int nErrorCode) to'CuPkT
{ ypgM&"eR
System.err.println("Error Code : " + nErrorCode); M1]}yTCd
} R< L =&I
w4fQ~rcUIc
?[uHRBR'
//停止文件下载 C :An
public void siteStop() g>@a
{ bg!(B<!X
bStop = true; dF[|9%)
for(int i=0;i<nStartPos.length;i++) hF{gN3v5
fileSplitterFetch.splitterStop(); ^RJ@9`P&t
9Fy'L#%
le' Kp V
} OwT_W)$
} ,CI-IR2
//负责部分文件的抓取 a>6D3n W
**FileSplitterFetch.java Q6HghG
*/ TQu.jC
package NetFox; =w* 8
I 12Zh7Cc:
ufe|I
import java.io.*; ?YMBZ
import java.net.*; `Se2f0",
@ta:9wZ
h\p!J-V
public class FileSplitterFetch extends Thread { E~#G_opQA
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String sURL; //File URL .*f6n|
long nStartPos; //File Snippet Start Position Xt:$H6 y
long nEndPos; //File Snippet End Position s=]NKJaQH
int nThreadID; //Thread's ID HUMy\u84H
boolean bDownOver = false; //Downing is over gV-*z}`U
boolean bStop = false; //Stop identical u]Q}jqiq"
FileAccessI fileAccessI = null; //File Access interface `#'j3,\6
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException o5j6(`#;
{ Yn[>Y)
this.sURL = sURL; j^5YFUwsQg
this.nStartPos = nStart; [-VK!9pQ
this.nEndPos = nEnd; Qu1&$oO
nThreadID = id; G pI4QzR
fileAccessI = new FileAccessI(sName,nStartPos);//定位 cxQAp
} "P0!cY8r
.^M#BAt2
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public void run() M(nzJ
{ I`(53LCqo
while(nStartPos < nEndPos && !bStop) m94PFD@N
{ Q=8YAiCu
%g:'6%26
~&<t++ g
try{ =
URL url = new URL(sURL); ?QmtZG.$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !qp$Xtf+
httpConnection.setRequestProperty("User-Agent","NetFox"); "0uM%*2
String sProperty = "bytes="+nStartPos+"-"; AmHj\NX$
httpConnection.setRequestProperty("RANGE",sProperty); (~eS$8>.
Utility.log(sProperty); _7\`xU
sQ340!
pbEWnx_
InputStream input = httpConnection.getInputStream(); g<(!>:h
//logResponseHead(httpConnection); >O<a9wz
#Lpw8b6
`kuu}YUi
byte[] b = new byte[1024]; u178vby;l
int nRead; Ovc9x\N
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) i%!<6K6UT
{ pHoHngyi&
nStartPos += fileAccessI.write(b,0,nRead); -yB}(69
//if(nThreadID == 1) ;&n iZKoe
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y%ij)vQY
} $1"gFg
u3#+fn_
u.|%@
Utility.log("Thread " + nThreadID + " is over!"); \wD/TLS}
bDownOver = true; ,{!,%]bC
//nPos = fileAccessI.write (b,0,nRead); qF4tjza;k
} "d:rPJT)(@
catch(Exception e){e.printStackTrace ();} vRH^en
} r}&&e BY f
} FJDC^@Ne
*djLf.I@
:`NZD
//打印回应的头信息 XrM+DQ;
public void logResponseHead(HttpURLConnection con) ij!d-eM/b
{ 4P[MkMoC
for(int i=1;;i++) kBhjqI*
{ e2v`
String header=con.getHeaderFieldKey(i); e,epKtL
if(header!=null) VS/M@y_./
//responseHeaders.put(header,httpConnection.getHeaderField(header)); l>K+4
Utility.log(header+" : "+con.getHeaderField(header)); cN0 *<
else <wk
break; 6`O,mpPu4G
} ed`"xm
} \894Jqh
=X?fA,
U!o7Nw@z
public void splitterStop() m{Vd3{H40
{ 7H)$NG<U$
bStop = true; ,eBC]4)B6
} beBG40
aaig1#a@1b
}ofb]_C,
} g}v](Q
&Gh0f"?
4WvW11q8U
/* T/g\v?>
**FileAccess.java R1X'}#mU
*//文件访问(定位，写) .*x:
package NetFox; w[ v{)
import java.io.*; mFF4qbe
>2znn&gZ
84QOW|1
public class FileAccessI implements Serializable{ P !i_?M
k}v`UiGM
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >^~^#MT
RandomAccessFile oSavedFile; @w8}]S
long nPos; w2.] 3QAZ
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H[u9C:}9b
public FileAccessI() throws IOException c'i5,\#X
{ gSwV:hm
this("",0); fgd2jr3T
} x|a&wC2,{
iT :3e%
4%J0e'iN
public FileAccessI(String sName,long nPos) throws IOException ot<d FvD
{ [*^.$s(
oSavedFile = new RandomAccessFile(sName,"rw"); ,gVVYH?qR
this.nPos = nPos; E`oA(x7l
oSavedFile.seek(nPos); E xhih^[_
} MvpJ0Y (
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9s^$tgH
public synchronized int write(byte[] b,int nStart,int nLen) QMBT8x/+_'
{ bFX{|&tHU
int n = -1; KkZx6A)$u
try{ M YF ^zheD
oSavedFile.write(b,nStart,nLen); /eQAGFG
n = nLen; p75o1RU
} LZn'+{\`
catch(IOException e) :|s8v2am
{ zG#5lzIu,
e.printStackTrace (); F,Q;sq
} oRCc8&
'nq=xi@RC
'IX1WS&\"
return n; L*Z.T^h
} 9m M3Ve*
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"@&TC"YG0
} <2U@O` gC
~o!-[
%*gf_GeM
/* J=^IS\m
**SiteInfoBean.java "tCTkog3]
*/ `MVqd16Y
package NetFox; G x[ZHpy;
L(TM& ps\-
P~trxp=k
public class SiteInfoBean { @GN2v,WA?
0SL{J*S4[#
PyQ.B*JJ
private String sSiteURL; //Site's URL S[F06.(1
private String sFilePath; //Saved File's Path -'$ob~*
private String sFileName; //Saved File's Name +]%S}<R
private int nSplitter; //Count of Splited Downloading File T'5{p
|Mq+QDTTw~
b)I-do+
public SiteInfoBean() 5*$yY-A
{//nSplitter的缺省值为5 Cq2Wpu-u
//default value of nSplitter is 5 k4ti#3W5eG
this("","","",5); Bz ;r<Kn
} Mh7m2\fLbd
yiZtG#6K{
m;dwt1'Zw
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) >R F|Q
{ 2$Mnwxfk
sSiteURL= sURL; >$ZG=&
sFilePath = sPath; oN1D&*
sFileName = sName; l ;:IL\*1I
this.nSplitter = nSpiltter; }Z"iW/?"
-$Z1X_~;)<
f)*"X[)o
} 6YM X7G]
%Ln`c.C
6HY): M&?
public String getSSiteURL() "|8oFf)l@B
{ aO&U=!
return sSiteURL; 5%Qxx\q
} L0g+RohW
[KK |_
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public void setSSiteURL(String value) (GmBv
{ ^j\LB23
sSiteURL = value; h0PDFMM<
} *9j'@2!M
8S1@,O,
Pp_4B
public String getSFilePath() 7S{qo&j'
{ A"JdG%t>.h
return sFilePath; fa/S!%}fO
} EsGu#lD2
O@Aazc5K
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public void setSFilePath(String value) XKjrS 9:
{ #%E`~&[
sFilePath = value; *E/Bfp1LIe
} y*iZ;Bv j
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/whaY4__O\
public String getSFileName() ,{0Y:/T'
{ =?OU^u`C
return sFileName; _N`.1Dl%Q
} ?Y~t{5NJR
WN'AQ~qA
$@z77td3
public void setSFileName(String value) g"P%sA/E+
{ o'DtW#F
sFileName = value; v+nXKNL
} ZexC3LD"
cI2Ps3~"Q
H a!,9{T
public int getNSplitter() D^[l~K
{ z0}j7ns]
return nSplitter; <Q|\mUS6
} 9lYKG^#D
{W,5]-
&BPYlfB1
public void setNSplitter(int nCount) d1D f`
{ << 6GE
nSplitter = nCount; Cf[tNq
} roS" q~GS,
} d {!P c<
, /.@([C
T~]~'+<Pi
/* *wTX
**Utility.java W3.[d->X
*/ `yfZ{<
package NetFox; 0nwi5
<j'K7We/tP
9+1{a.JO
public class Utility { _5p$#U`
R (f:UC
doanTF4Da
public Utility() |=}+%>y_
{ %L.S~dN6
Ux_tzd0!
s 4`-mIa
} lO-DXbgql$
jW:7PS
//线程睡眠 :4{ `c.S
public static void sleep(int nSecond) E/:U,u{
{ #z(:n5$F
try{ %],BgLhS.
Thread.sleep(nSecond); puOtF YZ\
} rp@:i _]
catch(Exception e) gNZwD6GMe?
{ 3WwS+6R
e.printStackTrace (); >j?5?J"
} ;dzy5o3
} ]ae(t`\l^
!`{?qQ[=
//日志 s$#64"F
public static void log(String sMsg) &[d'g0pF
{ zB%~=@Q^6
System.err.println(sMsg); 0!\gK<,z
} 6{+yAsI
L2VwW
@)b'3~D
public static void log(int sMsg) ko}& X=
{ (>}1t!1
System.err.println(sMsg); \:m~ +o$<-
} c^W;p2^
} 5HbHJ.|r
&y_t,8>5
Wet0qt]
/* )?jFz'<r
**TestMethod.java ?T/4 =
*/ k4sV6f
package NetFox; ^2'Y=g>
<f7 O3 >
.BPd06y
public class TestMethod { 0ca0-vY
mlByE,S2E
t!\aDkxo %
public TestMethod() w[z=x
{ ///xx/weblogic60b2_win.exe :%gc Sm
try{ EE'2<"M
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #4AU&UM+i
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 12^uu)6Xm,
SiteFileFetch fileFetch = new SiteFileFetch(bean); <Y)14w%
fileFetch.start(); oywPPVxj
} v/ry" W
catch(Exception e){e.printStackTrace ();} ranem0KQ)]
phDIUhL$z
1sXCu|\q
} "==c
"W5MZ
|)7K(R)(=
public static void main(String[] args) `he# !"
{ Z.${WZW
new TestMethod(); @*hv|zjs
} XGZZKvp
} Ny"9!3V
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