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)); iDltN]zS
} ^E~1%Md.
for(int i=0;i<nEndPos.length-1;i++) W[>qiYf^b
{ e-VGJxR
nEndPos = nStartPos[i+1]; 7=&+0@R#/d
} 0}'/3Q
nEndPos[nEndPos.length-1] = nFileLength; K%u>'W
} v`p@djM
} (aq-aum-I
4i<GqG
vV"I}L
//启动子线程 QcjsQTAbk
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; NH*"AE;
for(int i=0;i<nStartPos.length;i++) 7Rc>LI* '
{ UVW4KUxR
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vjA!+_I6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), @twi<U_
nStartPos,nEndPos,i); r>sXvzv
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \c!e_rZ
fileSplitterFetch.start(); #CW{y?=
} gN*b~&G
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {xICR ~,*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); l j+p}dt
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", k"m+i
nEndPos = " + nFileLength); t%@u)bp
// fileSplitterFetch[nPos.length-1].start(); ~3%aEj
TKVS%//
xZ SDA8kS
//等待子线程结束 ]Z52L`k
//int count = 0; S@TfZ3Go|
//是否结束while循环 &MB1'~Q,hq
boolean breakWhile = false; ~n(LBA
bkrl>Im<n
*nv^s
while(!bStop) CdtCxy5
{ vN~joQ=d
write_nPos(); !Y/S2J
Utility.sleep(500); ]3Jb$Q@
breakWhile = true; C^:{y
~4xn^.w
,|j\x
for(int i=0;i<nStartPos.length;i++) KTeR;6oZn"
{ k`s_31<
if(!fileSplitterFetch.bDownOver) 0n={Mb
{ Z>dvth
breakWhile = false; r"t,/@`n
break; bw!*=<
} 1Ve~P"w
} ~B7<Yg
if(breakWhile) W*,$0 t
break; 0_=^#r4Mu
}1Q>A 5e
ZS`9r16@b
//count++; ;q#Pl!*5
//if(count>4) GgE 38~A4
// siteStop(); j(M.7Z7^
} Bw9O)++
Xo6zeLHO
-U\s.FI.AR
System.err.println("文件下载结束！"); $+,kibk*R
} g!)*CP#;
catch(Exception e){e.printStackTrace ();} 5,\|XQA5!
} E 5mYFVK
Q9Go}}n
m6Qm }""
//获得文件长度 e2pFX?
public long getFileSize() 2(P<TP._E
{ 1O1MB&5%
int nFileLength = -1; -$,'|\Y
try{ Owv}lJ
URL url = new URL(siteInfoBean.getSSiteURL()); n;QFy5HB8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _:Jma
httpConnection.setRequestProperty("User-Agent","NetFox"); p[;@9!t
8~O0P=
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int responseCode=httpConnection.getResponseCode(); O5:[]vIn
if(responseCode>=400) A+z}z@K
{ O:8Ne*L`D
processErrorCode(responseCode); =NWzsRl,
return -2; //-2 represent access is error tJm1Q#||
} ):n'B` f}z
3-)R'
gf^y3F[\
String sHeader; c(!pcB8
b=SCyGxlZ5
q2;CvoF
for(int i=1;;i++) `trcYmR=k
{ 6LqF*$+$`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Hr \vu`p$
//Utility.log(in.readLine()); kPO+M~+n
sHeader=httpConnection.getHeaderFieldKey(i); w8#ji 1gX
if(sHeader!=null) i8#:y`ai
{ 162Dj$
if(sHeader.equals("Content-Length")) &G?w*w_n
{ ~ cI`$kJ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 08g2? 5w"
break; >x ]{cb/m
} U}l=1B
} at\$ IK_
else O>9-iqP>`d
break; v9Lf|FXo&
} 2;w> w#}>
} iT+t
catch(IOException e){e.printStackTrace ();} lbh7`xCR
catch(Exception e){e.printStackTrace ();} /XdLdA!v
&3itBQF
zKh<zj
Utility.log(nFileLength); ViUx^e\
}n +MVJ;dG
hI*6f3Vn(n
return nFileLength; 'u_j5
} W'e{2u
TxTxyYd
mqY=N~/O
//保存下载信息（文件指针位置） gb}ov**
private void write_nPos() }^*`&Lh
{ qV-1aaA
try{ uX6rCokr
output = new DataOutputStream(new FileOutputStream(tmpFile)); & sXMB
output.writeInt(nStartPos.length); sXY{g0%
for(int i=0;i<nStartPos.length;i++) o?aF
{ g``S SU
// output.writeLong(nPos); c4bvJy8
output.writeLong(fileSplitterFetch.nStartPos); 7Oi<_b
output.writeLong(fileSplitterFetch.nEndPos); t&IWKu#
} +KOhDtLMG
output.close(); _<?z-K_;I
} L:.Rv0XT
catch(IOException e){e.printStackTrace ();} {yMkd4v
catch(Exception e){e.printStackTrace ();} "S>VqvH3
} ZbH_h]1$D
j_b/66JyN
iaQFVROu
//读取保存的下载信息（文件指针位置） Z5`V\$
private void read_nPos() PH?<)Wj9i
{ EEvi_Z932
try{ 51ILR9 Bc_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (.b!kfC
int nCount = input.readInt(); 9QeBz`lm)
nStartPos = new long[nCount]; <1`MjP*w
nEndPos = new long[nCount]; OfeM;)
for(int i=0;i<nStartPos.length;i++) INRRA
{ },O7NSG<o
nStartPos = input.readLong(); Qh]k)]+*|
nEndPos = input.readLong(); ]|[mwC4
} 7(H?3)%0
input.close(); }$* z:E
} Q_*.1L
catch(IOException e){e.printStackTrace ();} [lzH%0 V
catch(Exception e){e.printStackTrace ();} AR g]GV/L
} |Vp ?
ZR8y9mx2"
V-"#Kf9
private void processErrorCode(int nErrorCode) aaI5x
{ SXV2Y-
System.err.println("Error Code : " + nErrorCode); <irr.O
} EWWCh0 {
JZqJ&
eUD 5V
//停止文件下载 {<cgeH
public void siteStop() KSUhB
{ af/0e}-
bStop = true; J@rBrKC
for(int i=0;i<nStartPos.length;i++) Ki /j\
fileSplitterFetch.splitterStop(); JQW7y!Z
2N.!#~_2D
V0_^==Vs
} d^"|ESQEU
} hzh3p[
//负责部分文件的抓取 $]a*ZHd;2&
**FileSplitterFetch.java r_o\72
*/ X#X/P
package NetFox; J~N!. i
}x_:v!G
{H 3wL
import java.io.*; .EjjCE/v-
import java.net.*; DH.CAV
zXe]P(p<
8C I\NR{x8
public class FileSplitterFetch extends Thread { :aD_>,n
s2#}@b6'.
<co:z<^lqu
String sURL; //File URL }G"bD8+
long nStartPos; //File Snippet Start Position A'*#UYn(
long nEndPos; //File Snippet End Position LDDt=HEY4
int nThreadID; //Thread's ID 2=|Ks]<P
boolean bDownOver = false; //Downing is over Jb)xzUhES
boolean bStop = false; //Stop identical FWLLbL5t
FileAccessI fileAccessI = null; //File Access interface '"6*C*XS
8]4W@~c
xk^`4;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /8/N
{ ]Bz.6OR
this.sURL = sURL; HrRw
this.nStartPos = nStart; V\AF%=6}
this.nEndPos = nEnd; }3-`e3
nThreadID = id; WHRBYq_
fileAccessI = new FileAccessI(sName,nStartPos);//定位 02^Nf7DMR
} )t,efg
`mquGk|)
tHFUV\D;,
public void run() ;NGSJfn
{ 66po SZR@
while(nStartPos < nEndPos && !bStop) m;vm7]5
{ l_ LH!Tu
HUel
Q@Cy\l
try{ ];QX&";Z
URL url = new URL(sURL); +t(Gt0+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !{A#\~,
httpConnection.setRequestProperty("User-Agent","NetFox"); l4^MYwFR{O
String sProperty = "bytes="+nStartPos+"-"; :6Gf@Z&+
httpConnection.setRequestProperty("RANGE",sProperty); iq5-eJmq
Utility.log(sProperty); W QeQ`pM
[] R8VC>Ah
GwmYhG<{
InputStream input = httpConnection.getInputStream(); G6X5`eLQ
//logResponseHead(httpConnection); -I~\
`L3{y/U'
:T#f&|Gg;
byte[] b = new byte[1024]; Mp@dts/|
int nRead; =3GgfU5k
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~;oaW<"
{ IkQ,#Bsb[
nStartPos += fileAccessI.write(b,0,nRead); bFJ>+ {#
//if(nThreadID == 1) 9Wdx"g52_D
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r$,Xv+}
} -hGLGF??
$8Gj9mw4e'
mD,fxm{G
Utility.log("Thread " + nThreadID + " is over!"); &InFC5A
bDownOver = true; gbFHH,@
//nPos = fileAccessI.write (b,0,nRead); L(HAAqRnJ
} +y 48.5
catch(Exception e){e.printStackTrace ();} mS+sh'VH
} ZD<e$PxxCd
} O 2+taB
f~f)6XU|
=@d->d
//打印回应的头信息 iVb7>d9}
public void logResponseHead(HttpURLConnection con) /7WdG)'
{ `_3Gb
for(int i=1;;i++) ?4_ME3$t
{ t*Z4&Sy^
String header=con.getHeaderFieldKey(i); .F0Q<s9
if(header!=null) h<g2aL21?F
//responseHeaders.put(header,httpConnection.getHeaderField(header)); VD+v\X_
Utility.log(header+" : "+con.getHeaderField(header)); |[$TT$Fb
else 7_L$XIa
break; t~Qj$:\
} -CTLQyj)
} a*nCvZ
_DYe<f.
Pt/F$A{Cj
public void splitterStop() b\UE+\a&
{ )vGxF}I3
bStop = true; Y 9BKd78Y
} +[[^W;<.l
R'^J#"[
eo&G@zwN
} zuJ@@\75
m=60a@o]
g2YE^EKU~
/* z#6(PZC}
**FileAccess.java z7&m,:M
*//文件访问(定位，写) =RHIB1
package NetFox; l(8@?t^;
import java.io.*; #d$lN}8
r>6FJ:Tx
:,.HJ[Vg&
public class FileAccessI implements Serializable{ ~eXI}KhBw6
$?DEO[p.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,2mq}u>WU
RandomAccessFile oSavedFile; m1RjD$fM
long nPos; q<cxmo0S
>oapw5~5
<Kk?BRxi
public FileAccessI() throws IOException Xc<Hm
{ hwSxdT6
this("",0); ?2K~']\S
} l=<},_]{
u&e?3qKX(
w3"%d~/[x
public FileAccessI(String sName,long nPos) throws IOException n9V8A[QJ
{ 5e^z]j1Yv
oSavedFile = new RandomAccessFile(sName,"rw"); i4)]lWnd
this.nPos = nPos; FaKZ|~Y e
oSavedFile.seek(nPos); RG_6& A
} y]uBVn'u
}-p-(
#r@>.S=U]
public synchronized int write(byte[] b,int nStart,int nLen) .i1|U8"X
{ 88l{M[B2
int n = -1; p\tA&>3-
try{ .+5;AtN
oSavedFile.write(b,nStart,nLen); & z5:v-G?
n = nLen; dA0o{[o=
} fjm3X$tR
catch(IOException e) Y0ACJ?|
{ l7(p~+o?h>
e.printStackTrace (); QiNLE'19^
} 27Vx<W
CW,|l0i
e_3B\59k
return n; "j=E8Dd}
} ,8stEp9~h]
{&nDm$KTD
QM{B(zH
} Ib"fHLWA^!
Cjj(v7[E
H:mcex
/* Li\b,_C
**SiteInfoBean.java jOL=vG
*/ lN_b&92
package NetFox; gj82qy\:
-'Z-8
fBKN?]BdN
public class SiteInfoBean { (Vt5@25JW
Q>TNzh
jV#1d8qm
private String sSiteURL; //Site's URL WPPDvB
private String sFilePath; //Saved File's Path /`7G7pQ+
private String sFileName; //Saved File's Name J!yK/*sO,
private int nSplitter; //Count of Splited Downloading File M[L@ej
8]WcW/1r !
s 4n<k]d
public SiteInfoBean() i1!Y{
{//nSplitter的缺省值为5 &0OH:P%
//default value of nSplitter is 5 B.#-@
this("","","",5); |oR#j `
} vhN6_XD
.GvZv>
{T3wOi
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) X @X`,/{X
{ 4hW:c0
sSiteURL= sURL; tD]vx`0>
sFilePath = sPath; LftzW{>gI"
sFileName = sName; jK2gc^"t
this.nSplitter = nSpiltter; y 48zsm{
/Ur]U w
peVzF'F
} #/)U0IR)
r<'B\.#tp>
9/O\769"'
public String getSSiteURL() ULxgvq
{ \mw5 ~Rf;
return sSiteURL; >dwY(a
} Hh%|}*f_,
'i 8`LPQ
pMkM@OH
public void setSSiteURL(String value) +l<;?yk:;
{ pK)!o
sSiteURL = value; q[c^`5
} F`o"t]AD-a
unyU|B
\3O1o#=(
public String getSFilePath() ,N8SP 'R
{ yg"FF:^T
return sFilePath; Q>uJ:[x+
} R)%I9M,
~_ko$(;A
&& WEBQ
public void setSFilePath(String value) S*H @`Do%d
{ \_/dfmlIZ
sFilePath = value; MFqb_q+
} P} Y .
"}:SXAZ5`
:PBW=W
public String getSFileName() m2Wi "X(I_
{ LKst QP!I
return sFileName; B8zc#0!1
} `bZgw
^C;ULUn3
|43Oc:Ah+
public void setSFileName(String value) 'NDr$Qc3
{ r^,"OM]
sFileName = value; #}[NleTVt
} U+VyH4"
y.::d9v
iL'j9_w,
public int getNSplitter() l^rQo_alk
{ D~ 7W
return nSplitter; FMC]KXSd
} {G{>Qa|
]m#*4
v+'*.Iv:
public void setNSplitter(int nCount) {%6g6?=j
{ ,jeC7-tX
nSplitter = nCount; <,Jx3yq
} 24 RD
} Kae-Y
\ F)}brPc
LmPpt3[
/* )&ucX
**Utility.java ghW
*/ eqqnR.0
package NetFox; i\kDb=
Nu+DVIM
z]!w@:
public class Utility { i~rb-~o
rg I Z
|]b,% ?,U
public Utility() fRp(&%8E
{ X5=I{eY}
fPG3$<Zr
,Eo\(j2F.
} h/*@ML+bB8
dyl1~'K^
//线程睡眠 n39EKH rm%
public static void sleep(int nSecond) _U Y5
{ cuL/y$+EY
try{ uz;eYD
Thread.sleep(nSecond); l6.&<0pLT
} ?3<Y/Vg%c
catch(Exception e) Fp>nu_-"
{ LXf|n
e.printStackTrace (); 40 zO4
} c,}VC-
} xggF:El3{
\9]-(j6[H
//日志 imyfki $B
public static void log(String sMsg) Au*1-
{ c~!ETwpHQ
System.err.println(sMsg); .>Fpk7
} 877Kv);
'Qg.D88
&5QvUn
public static void log(int sMsg) x|g2H.n
{ 8[:G/8VI
System.err.println(sMsg); Nop61zj
} /`j2%8^N
} g-cg3Vso
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/* \ZBz]rh*
**TestMethod.java \xmDkWzE
*/ _AH_<Z(
package NetFox; <|hrmwk|
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zO0K*s.yK
public class TestMethod { c,#Nd@
@[{5{ y
rVp^s/A^;
public TestMethod() @?& i
{ ///xx/weblogic60b2_win.exe IH.EvierJ
try{ LVdtI
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (*\y
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); LdnTdh?
SiteFileFetch fileFetch = new SiteFileFetch(bean); @@=,bO
fileFetch.start(); TW=N+ye^1(
} {,= hIXo>
catch(Exception e){e.printStackTrace ();} _WI~b
ZHCrKp
A>\3FeU>UC
} (R(NEN
Bk5ft4v-
SBY0L.
public static void main(String[] args) ^!x qOp!
{ n%!50E6*:
new TestMethod(); %1)JRc
} zbfe=J4c
} .`oKd@I*"
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