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)); .[NB"\<q
} {Jwh .bJ
for(int i=0;i<nEndPos.length-1;i++) !z$.Jcr1
{ K1]H~'
nEndPos = nStartPos[i+1]; J9zSBsp_
} (%YFcE)SRS
nEndPos[nEndPos.length-1] = nFileLength; iE!\)7y
} j"9bt GX
} O4S~JE3o
vzd1:'^t
?ep93:j
//启动子线程 lqTTTk
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bO8g#rO
for(int i=0;i<nStartPos.length;i++) &2d^=fih
{ -uHD| }
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -O:+?gG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Np$pz
nStartPos,nEndPos,i); (:4N#p
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 67wY_\m9I
fileSplitterFetch.start(); s=h
} rzsb(
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), o['HiX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); LJt#c+]Li
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", imv[xBA(d
nEndPos = " + nFileLength); YIvJN
// fileSplitterFetch[nPos.length-1].start(); XXBN Nr_CK
y1GVno
wt0^R<28
//等待子线程结束 meA=lg?
//int count = 0; lTBPq?4{
//是否结束while循环 K[!OfP
boolean breakWhile = false; Ri=>evx
mtSOygd
ACxOC2\n
while(!bStop) `xMmo8u4
{ {4SwCN /
write_nPos(); >~8;H x].d
Utility.sleep(500); pC2ZN
breakWhile = true; BQu_)@
aw&:$twbM
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for(int i=0;i<nStartPos.length;i++) J6r"_>)z
{ uu@Y]0-
if(!fileSplitterFetch.bDownOver) %xF j;U?
{ 1RpTI7
breakWhile = false; ufyqfID
break; 4=!SG4~o
} 6;6a.iZ
} Fr_esx
if(breakWhile) bL soKe
break; o!!";q%DX
-e0C Bp
3NAU|//J
//count++; ~b;l08 <
//if(count>4) Z^5j.d{e$
// siteStop(); golr,+LSo
} O_^O1
3 r4QB
-;9pZ'r
System.err.println("文件下载结束！"); AT Dm$ *
} `7_=2C
catch(Exception e){e.printStackTrace ();} 65X31vU
} &Uq++f6
v0hr~1
/^ *GoB
//获得文件长度 banie{ e
public long getFileSize() 2ED^uc: 0S
{ y Nb&;E7 H
int nFileLength = -1; juOOD
try{ DE"KbA0}
URL url = new URL(siteInfoBean.getSSiteURL()); DwM4/m
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [GKSQt{)
httpConnection.setRequestProperty("User-Agent","NetFox"); 7 +A-S9P)
AdBF$nn[
;m6Mm`[i<
int responseCode=httpConnection.getResponseCode(); l*]9
if(responseCode>=400) jCdKau&9
{ p_h)|*W{
processErrorCode(responseCode); 8qwc]f$.w
return -2; //-2 represent access is error <qZ"W6&&
} _\yrR.HIa
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2y; |6`
String sHeader; 7+]T}4;
86d*
.gUceXWH3
for(int i=1;;i++) ,])@?TJb@
{ "h.}o DS
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); VU,\OOp
//Utility.log(in.readLine()); il^SGH
sHeader=httpConnection.getHeaderFieldKey(i); : sIZ+3
if(sHeader!=null) i(.c<e{v~
{ ,Ie~zZE&
if(sHeader.equals("Content-Length")) xo{f"8}^
{ EFeG[bxM
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x)<5f|j
break; v8g3]MVj3
} y@g{:/cmO
} _DfI78`(
else Yjz'lWg
break; AfvTStwr
} j}YZl@dYV
} o:C:obiQbu
catch(IOException e){e.printStackTrace ();} @'[w7HsJ
catch(Exception e){e.printStackTrace ();} b7fP)nb695
~h-G
p}uTqI
Utility.log(nFileLength); 2^Gl;3
M"F?'zTkJ
#I9|>XE1
return nFileLength; Lc^nNUzPo
} /b@0HL?
:j$K.3n
THQW8 V
//保存下载信息（文件指针位置） 4@#1G*OO
private void write_nPos() 7-Rn{"5
{ ZTd_EY0q
try{ tjkY[
output = new DataOutputStream(new FileOutputStream(tmpFile)); aq"E@fb
output.writeInt(nStartPos.length); i2b\` 805
for(int i=0;i<nStartPos.length;i++) 9.e?<u*-z
{ d%9I*Qo0,
// output.writeLong(nPos); Wf_aEW&n
output.writeLong(fileSplitterFetch.nStartPos); 0<{/T*AU:
output.writeLong(fileSplitterFetch.nEndPos); O60jC;{F
} tZ>>aiI3
output.close(); aGp <%d
} -a3+C,I8g
catch(IOException e){e.printStackTrace ();} _wM[U`H}s
catch(Exception e){e.printStackTrace ();} b7v] g]*
} ?>q=Nf^Q.
i#lvt#2J0
8q7KqYu
//读取保存的下载信息（文件指针位置） doc5;?6
private void read_nPos() psRm*,*O
{ SfJ/(q
try{ &\sg~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i40r}?-
int nCount = input.readInt(); dG7sY O@U
nStartPos = new long[nCount]; pRc(>P3;
nEndPos = new long[nCount]; pzU">)
for(int i=0;i<nStartPos.length;i++) d;lp^K M
{ R$,`}@VqZ3
nStartPos = input.readLong(); (]1le|+
nEndPos = input.readLong(); yF0,}
} 1b3Lan_2
input.close(); (/"T=`3t
} ]CC~Eo-%-
catch(IOException e){e.printStackTrace ();} 3{MIBMA
catch(Exception e){e.printStackTrace ();} e7#=F6
} 8x,;B_Zu
I]SR.Yp%
h:bs/q+-
private void processErrorCode(int nErrorCode) D4#,9?us
{ T>f-b3dk
System.err.println("Error Code : " + nErrorCode); 8QC:ro
} ,7%(Jj$ ^
Bl`e+&b
P\zi:]h[Gh
//停止文件下载 k}T~N.0
public void siteStop() 3'/wRKl
{ <Isr
bStop = true; eHnC^W}|s
for(int i=0;i<nStartPos.length;i++) A5H[g`&
fileSplitterFetch.splitterStop(); ;4qalxzu
|um)vlN;9
Be]o2N;J
} \17)=W
} $^ >n@Q@&L
//负责部分文件的抓取 ^E:;8h4$9
**FileSplitterFetch.java :sA-$*&x
*/ -5>g 0o2
package NetFox; >LLzG
*n[Fl
I" j7
import java.io.*; R,^FJ
import java.net.*; 6|jE3rHw
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F H%yyT
public class FileSplitterFetch extends Thread { SfR!q4b=
ljf9L:L
DHJnz>bE
String sURL; //File URL @%fkW"y:
long nStartPos; //File Snippet Start Position Z'j<wRf
long nEndPos; //File Snippet End Position jyT(LDsS
int nThreadID; //Thread's ID &WRoNc
boolean bDownOver = false; //Downing is over m76]INq
boolean bStop = false; //Stop identical 2 rBF<z7
FileAccessI fileAccessI = null; //File Access interface &a(w0<
iH$N HfH
D@ lJ^+
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @v'<~9vG
{ #]'V#[;~
this.sURL = sURL; Pb`sn5;
this.nStartPos = nStart; v m$v[
this.nEndPos = nEnd; F3f>pK5
nThreadID = id; wvYxL c#p0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >L(F{c:
} qqAsh]Z
jGWLYI=V2
s1FBz)yCY=
public void run() *Xo f;)Z^
{ 8]L.E
while(nStartPos < nEndPos && !bStop) GJ$,@
{ 3_>1j
. =5Jpo
Qp54(`
try{ *~"`&rM(
URL url = new URL(sURL); !(~>-;A8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @88 efF
httpConnection.setRequestProperty("User-Agent","NetFox"); 0T5>i 0/
String sProperty = "bytes="+nStartPos+"-"; 7lpVK]
httpConnection.setRequestProperty("RANGE",sProperty); |)_R bqZ
Utility.log(sProperty); GwycSb1
P&YaJUq.u
w\ :b(I
InputStream input = httpConnection.getInputStream(); aVb]H0
//logResponseHead(httpConnection); Rt|Hma
Yp)U'8{h c
aFym&n\
byte[] b = new byte[1024]; a8 1%M
int nRead; ]4yvTP3[Rm
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6b|`[t
{ l.juys8s
nStartPos += fileAccessI.write(b,0,nRead); ""d>f4,S
//if(nThreadID == 1) yd~fC:_ ]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \2,18E
} $yAfs3/%)s
abnd U,s
w-$w
Utility.log("Thread " + nThreadID + " is over!"); o0L#39`'g
bDownOver = true; ar|[D7Xrq\
//nPos = fileAccessI.write (b,0,nRead); S+G)&<a^
} Anv8)J!9u
catch(Exception e){e.printStackTrace ();} d@tr]v5 B
} Yn>zR I
} q1Sm#_7
F21[r!3
r<v%Zp
//打印回应的头信息 5XI*I(.%/
public void logResponseHead(HttpURLConnection con) >G2-kL_
{ %#9~V
for(int i=1;;i++) uN 62>
{ \<B6>
String header=con.getHeaderFieldKey(i); [r8 d+
if(header!=null) VWy:U#;+8
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,d>~='
Utility.log(header+" : "+con.getHeaderField(header)); QtQ^"d65
else vs|6ww
break; 9Oyi:2A
} 8 -;ZPhN&
} ;|QR-m2/
+c`C9RXk
SsX05>
public void splitterStop() xm5FQ) T
{ FM"BTA:C
bStop = true; t[,T}BCy.
} gsWlTI
y%bqeo L~
>5Oy^u6Ly
} r/sRXM:3cZ
!a(qqZ|s
jnzz~:
/* MVP)rugU
**FileAccess.java Y~hd<8 ~
*//文件访问(定位，写) rqe_zyc&
package NetFox; k`mrRs
import java.io.*; 2G5!u)
'3UIriY6
nQ!#G(_nO
public class FileAccessI implements Serializable{ O\F^@;]F6
1qKxg
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _<F@(M5
RandomAccessFile oSavedFile; f9XO9N,hE:
long nPos; r]EZ)qp^@
2]RH)W86;
obc^<ZD]
public FileAccessI() throws IOException j X!ftm2
{ pkV\D
this("",0); k&_u\D"^"%
} B0XBI0w^Y
i~Ob( YIH
e9hVX[uq
public FileAccessI(String sName,long nPos) throws IOException QRZTT qG
{ OK2/k_jXN'
oSavedFile = new RandomAccessFile(sName,"rw"); q'AnI$!
this.nPos = nPos; :f !=_^}
oSavedFile.seek(nPos); - Zoo)
} ny_ kr`$42
@1SKgbt>
%)hIpxOrX
public synchronized int write(byte[] b,int nStart,int nLen) )>X|o$2
{ k5%0wHpk=
int n = -1; ]^6y NtLK
try{ 3|'#n[3
oSavedFile.write(b,nStart,nLen); C(1A8
n = nLen; >[%.h(h/%
} PxVI{:Uz
catch(IOException e) )3`
{ ?(NT!es
e.printStackTrace (); fF9oYOh|
} z1SMQLk
<j1d~XU}
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return n; B-ri}PA
} @F(3*5c_Y
J.e8UQ@=5
qp~4KukL
} \l=KWa3Q
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jQ_|z@OV
/* %X9:R'~sP
**SiteInfoBean.java ahi57r[
*/ RqN_vk\
package NetFox; X.T\=dm%v
QC\g%MVG
v1"g!%U6
public class SiteInfoBean { x,w`OMQ}c
{Z?$Co^R
rz[uuY7
private String sSiteURL; //Site's URL iQm.]A
private String sFilePath; //Saved File's Path %+7T9>+
private String sFileName; //Saved File's Name BudWbZ5>Ep
private int nSplitter; //Count of Splited Downloading File I"F .%re
)S wG+k,
=ve*g&
public SiteInfoBean() =_?pOq
{//nSplitter的缺省值为5 GEe 0@q#YA
//default value of nSplitter is 5 Q0L@.`~
this("","","",5); 7{Ki;1B[w
} b5n]Gp
I4o=6ts
dY4k9p8
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^ =/?<C4
{ 9Ew:.&d
sSiteURL= sURL; q2S!m6!
sFilePath = sPath; \&\_>X.,
sFileName = sName; Ha=_u+@
this.nSplitter = nSpiltter; u^aFj%}]L
EZ%w=
{w |dM#
} ==h|+NFa
l}Q"Nb)
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public String getSSiteURL() 9k=U0]!ch
{ B0b[p*gIl
return sSiteURL; 68koQgI[^
} "'z,[v50&
(b/A|hl
tT@w%Sz57N
public void setSSiteURL(String value) nOAJ9
{ tb:,Uf>E
sSiteURL = value; Ci7P%]9
} i}/e}s<-6
`1E|PQbWc
%YcxC0S[
public String getSFilePath() V>b2b5QAH,
{ T~i%j@Q.6
return sFilePath; ]>R`;"(
} e2]4a3
PGPISrf
HE#,(;1i
public void setSFilePath(String value) GBH_r0
{ EJf#f
sFilePath = value; g>2aIun_Q
} sU) TXL'_!
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v! 7s M
public String getSFileName() ?QCmSK=L
{ NFk}3w:
return sFileName; o&(wg(Rv
} T>}0) s
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public void setSFileName(String value) v8ba~
{ ;B&^yj&;
sFileName = value; x(L(l=^"
} ShQ|{P9
Fi mN?s
ojHhT\M`
public int getNSplitter() K&=D-50%
{ `/#f?Hk=
return nSplitter; o^3FL||P#r
} <fN; xIB
Zp?4uQ)[W
4-mVB wq
public void setNSplitter(int nCount) 3sH\1)Zz
{ 9YB2e84j
nSplitter = nCount; l , ..5
} .%q$d d>>
} ^YGTh0$W
8{dEpV*
PgMbMH
/* X0`j-*,FX
**Utility.java ; e@gO
*/ Yu'a<5f
package NetFox; Y9F)`17
nX|Q~x]
2nv[1@M
public class Utility { jpRBER_X
2-~|Z=eGW
Gqb])gXpl
public Utility() we3tx{j
{ (&jW}1D
?~J i-{#X
l _+6=u
} CK0l9#g
8-m 3e
//线程睡眠 FZF @
public static void sleep(int nSecond) ef=K_, _
{ 4:7mK/Z
try{ ?7 \\e;j}
Thread.sleep(nSecond); jfD1
} d|XmasGN
catch(Exception e) iib
{ +L0w;wT
e.printStackTrace (); +`B'r '
} d H? ScXM=
} r3qf[?3`6
y500Xs[c
//日志 :P$#MC
public static void log(String sMsg) D'b#,a;V
{ ]5' d&f
System.err.println(sMsg); +H_MV=A^
} .$&Q[r3Lu
(u hd "
{^}0 G^
public static void log(int sMsg) <@G8ni
{ `]=oo%(h
System.err.println(sMsg); ,lt8O.h-l
} maNW{"1
} t P"\J(x
AVl~{k|
HpVjee
/* k`\R+WK$
**TestMethod.java \( )#e
*/ @F~LW6K
package NetFox; /KCPpERk{
e5?PkFV^a1
qQ0C?
public class TestMethod { x%N\5 V1
`.%JjsD<
k|YWOy@D~
public TestMethod() amWD-0V
{ ///xx/weblogic60b2_win.exe cXnKCzSxZq
try{ QA#3bFZt1n
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); lFSe?X^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); dRi5hC$
SiteFileFetch fileFetch = new SiteFileFetch(bean); EW<kI+0D
fileFetch.start(); 8RW&r
} ?GA&f2]a
catch(Exception e){e.printStackTrace ();} FV39QG4b4
@n&<B`/
O#a6+W"U
} 23!;}zHp
ZR0r>@M3v<
en F:>H4
public static void main(String[] args) O81X;JdP3
{ ^].jH+7i*
new TestMethod(); .@q-B+Eg
} GoM ip8'u
} h}`!(K^;3
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