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)); A_g'9
} )TWf/Lcp
for(int i=0;i<nEndPos.length-1;i++) MF1u8Yl:0
{ [fb-G5x
nEndPos = nStartPos[i+1]; =#W{&Te;
} 3B_S>0H"$
nEndPos[nEndPos.length-1] = nFileLength; 41:Z8YL(
} 7#RW4ZM
} o(a*Fk$
AXJC&O}`
!~RD>N&n
//启动子线程 OZ-F+#d
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }3+(A`9h f
for(int i=0;i<nStartPos.length;i++) CocvEoE*z
{ y_'8m9Qy)
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gh~C.>W}q+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?6[>HX;
nStartPos,nEndPos,i); R)H@'X
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X4o8
fileSplitterFetch.start(); 4(Mt6{q
} 0!^{V:DtQ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R; IB o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4iKT
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", X`22Hf4ct
nEndPos = " + nFileLength); DZ EA*E>
// fileSplitterFetch[nPos.length-1].start(); !|}>Y
u!F3Rh8D
YX~H!6l
//等待子线程结束 '; qT
//int count = 0; Z(V4"x7F
//是否结束while循环 tV<Au
boolean breakWhile = false; M+ H$Jjcs
+xWT)h/
BtjsN22
while(!bStop) &)wQ|{P~k
{ j6Vuj/+}
write_nPos(); 7%0PsF _
Utility.sleep(500); ov|s5yH8e
breakWhile = true; }g`A*y;t
0z,c6MjM+
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for(int i=0;i<nStartPos.length;i++) DB?[h<^m
{ t4,6`d?C
if(!fileSplitterFetch.bDownOver) }U8H4B~UtY
{ Qz $1_vO
breakWhile = false; aZmSCi:&'
break; '&UX'Dd~Q
} 8(ZQD+U(9F
} T,;6q!s=
if(breakWhile) |vGz 1jLV
break; zRu}lJ1#W$
jtd{=[STU
hmks\eb~
//count++; (}}BZS&.
//if(count>4) ^d!-IL_
// siteStop(); l_$~~z ~
} /*st,P$"
5<&<61[A
b`1P%OjC
System.err.println("文件下载结束！"); Vj`9j. 5
} 1z{AzpMZ
catch(Exception e){e.printStackTrace ();} @1rF9< 4g
} 'os-+m@
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YsLEbue
//获得文件长度 ZJd1Lx
public long getFileSize() /SZsXaC '
{ Z!tt(y\
int nFileLength = -1; qA&N6`
try{ ;c~6^s`2
URL url = new URL(siteInfoBean.getSSiteURL()); ?e yo2:-$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e PlEd'Z
httpConnection.setRequestProperty("User-Agent","NetFox"); , Lhgv1
o D^],
*"4 OXyV
int responseCode=httpConnection.getResponseCode(); 3_ObCsJ#,
if(responseCode>=400) ]#_,?d
{ iv\?TAZC
processErrorCode(responseCode); NNSn]LP
return -2; //-2 represent access is error q1Ah!9B
} "o%N`Xlx
389T6sP]
\O`B@!da~
String sHeader; X,^J3Ek>O
G+=&\+{#4
'^n2]<
for(int i=1;;i++) &QLCij5:
{ 7G!SlC X}W
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); IZniRd;
//Utility.log(in.readLine()); /6b(w=pk
sHeader=httpConnection.getHeaderFieldKey(i); pn>zuHe
if(sHeader!=null) cKdy)T%;
{ ]MRE^Je\h
if(sHeader.equals("Content-Length")) QV7K~qi
{ A\k@9w\Ll;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); j<4J_wE
break; K4snpuhC
} \snbU'lfP
} 9kWyO:a_(
else 'l)@MXbGL
break; uXyNj2(d.
} |s[m;Qm[ku
} o~2bk<]z
catch(IOException e){e.printStackTrace ();} Ds$FO}KD{
catch(Exception e){e.printStackTrace ();} &}wKC:LSP
c-n'F+fZ
/%=p-By<V
Utility.log(nFileLength); _)ZAf%f?
m>jX4D7KZ
JPS L-j
return nFileLength; _LxV)
} (/Hq8o-Fw
r"zW=9 O=
m%'9zL c
//保存下载信息（文件指针位置） lKxv SyD
private void write_nPos() rM/*_0[`d
{ 6P3ezl@#;
try{ m{I_E G
output = new DataOutputStream(new FileOutputStream(tmpFile)); {M$mrmG
output.writeInt(nStartPos.length); 76 #
for(int i=0;i<nStartPos.length;i++) {y)s85:t
{ M\DUx5dJ,
// output.writeLong(nPos); #}^ZxEU
output.writeLong(fileSplitterFetch.nStartPos); )p).}"
output.writeLong(fileSplitterFetch.nEndPos); Xb&r|pR
} n)8bkcZCp+
output.close(); $Vlfg51ob
} s"=e(ob
catch(IOException e){e.printStackTrace ();} b=Zg1SqV
catch(Exception e){e.printStackTrace ();} XCDHd ?Ld
} >OBuHqC
NGd|7S[^+c
r9yUye}
//读取保存的下载信息（文件指针位置） ec)G~?FH
private void read_nPos() YEF%l'm(\
{ OHR9u
try{ ]j}zN2[A
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); lva]jh2
int nCount = input.readInt(); Q4Hf!v]r
nStartPos = new long[nCount]; v'TkKwl
nEndPos = new long[nCount]; B@63=a*kG
for(int i=0;i<nStartPos.length;i++) UFyGp>/06
{ rM2?"
nStartPos = input.readLong(); G$xuHHZ'
nEndPos = input.readLong(); ? Ls]k
} /#G^?2oM
input.close(); >6@*%LM
} k&n7_[]n
catch(IOException e){e.printStackTrace ();} lF8B+
catch(Exception e){e.printStackTrace ();} }V ;PaX
} @433?g`2b
tPDV"Md#m<
svU107?
private void processErrorCode(int nErrorCode) ygd'Nh!@
{ <Lyz7R6
System.err.println("Error Code : " + nErrorCode); X:j&+d2g0/
} F'C]OMBE
6(ju!pE`
o//N"S.)
//停止文件下载 U:J~Oy_Z
public void siteStop() O8[dPmW
{ )qzJu*cQ
bStop = true; qusgX;)
for(int i=0;i<nStartPos.length;i++) z }R-J/xr2
fileSplitterFetch.splitterStop(); <$Q&n{
Rdwr?:y(]
R 7xV{o
} S;Lqx5Cd
} t1n'Ecm(
//负责部分文件的抓取 9cQKXh:R.
**FileSplitterFetch.java nm*1JA.:
*/ OC7:Dp4
package NetFox; s,]6Lri`\
rfXM*h
fx99@%Ii
import java.io.*; K%2,z3ps
import java.net.*; 29,`2fFr
O>n L;I
n"@3d.21
public class FileSplitterFetch extends Thread { 9/~m837x
U11rj,7
f$*M;|c1c/
String sURL; //File URL P]yER9'
long nStartPos; //File Snippet Start Position *yiJw\DRN
long nEndPos; //File Snippet End Position O<L/m[]
int nThreadID; //Thread's ID )n5]+VTZ5
boolean bDownOver = false; //Downing is over MR#jI
boolean bStop = false; //Stop identical QkGr{
FileAccessI fileAccessI = null; //File Access interface h'MX{Wm.
qAivsYN*
X'7 T"5!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException jcXb@FE6
{ ##}a0\x|
this.sURL = sURL; I"Ju3o?u
this.nStartPos = nStart; ugVsp&i#
this.nEndPos = nEnd; h+R}O9BD
nThreadID = id; A>R ^iu
fileAccessI = new FileAccessI(sName,nStartPos);//定位 LL9I:^
} V=3NIw18
`zZ=#p/
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public void run() }{=%j~V;&
{ x03GJy5
while(nStartPos < nEndPos && !bStop) @U}fvdft
{ (0Hhn2JA
z<: 9,wtbP
T/-PSfbkj
try{ Vxo3RwmR
URL url = new URL(sURL); hYb!RRGn
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Nf<([8v;t
httpConnection.setRequestProperty("User-Agent","NetFox"); b[e+(X
String sProperty = "bytes="+nStartPos+"-"; 0kmVP~K
httpConnection.setRequestProperty("RANGE",sProperty); TD!QqLW
Utility.log(sProperty); 9#O"^.Z !
r[EN`AxDb
#/\FB'zC
InputStream input = httpConnection.getInputStream(); s8.oS);`
//logResponseHead(httpConnection); JOenVepQ,
`.L8<-]W
{BJ[h
byte[] b = new byte[1024]; e0v&wSi
int nRead; Z~T- *1V
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Vi5RkUY]
{ R0oP##]
nStartPos += fileAccessI.write(b,0,nRead); J*a`qU
//if(nThreadID == 1) }I05&/o.3p
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FjkE^o>
} 0sV;TQt+f
M;\K+,
L_ 8C=MS
Utility.log("Thread " + nThreadID + " is over!"); ]%>;R^HY
bDownOver = true; |Vd)7/LN
//nPos = fileAccessI.write (b,0,nRead); L|!9%X0.
} rIS \#j
catch(Exception e){e.printStackTrace ();} Rjm5{aa-
} <Ni]\-*
} D?X97jNm
J]fjg%C2m
ec"L*l"
//打印回应的头信息 q SCt=eQ
public void logResponseHead(HttpURLConnection con) uysGOyi<u
{ b4oZ@gVR;
for(int i=1;;i++) mgH4)!Z*56
{ 9FJU'$FN
String header=con.getHeaderFieldKey(i); ;v8,r#4
if(header!=null) )|Y"^K%Jm
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |`:Uww+3
Utility.log(header+" : "+con.getHeaderField(header)); 2&Wc4,O!i
else |}'}TYX0:
break; ")x9A&p
} ]%shs
} }tc,3>/
[S3X
h'IBVI!P
public void splitterStop() ~~'XY(\L@
{ lyv9eM
bStop = true; mIl^
} 3smcCQA%
6j_ A{*~Ng
1Voo($q.
} u8-)LOf(
vV"TTzs!
SGjaH8z
/* -$[=AqJXp;
**FileAccess.java M7!&gFv8
*//文件访问(定位，写) s)xfTr_$
package NetFox; 8l;0)`PU
import java.io.*; Z-]d_Y~m4
qX-Jpi P
!=k\Rr@qx
public class FileAccessI implements Serializable{ _%Mu{Ni&
w;r-TLf
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 p5G O@^i
RandomAccessFile oSavedFile; B^{bXhDp
long nPos; N#]f?6*R
H-7*)D
/c__{?go
public FileAccessI() throws IOException /EKfL\3
{ *R1x^t+)
this("",0); 2ORWdR.b
} 8=)Aksu
C=%go1! $
NjsP"
public FileAccessI(String sName,long nPos) throws IOException B]Yj"LM)
{ $T]1<3\G
oSavedFile = new RandomAccessFile(sName,"rw"); -"!V&M
this.nPos = nPos; #@lr$^M
oSavedFile.seek(nPos); /KlA7MH6
} R/< /g=
gh i!4
*b7HtUA
public synchronized int write(byte[] b,int nStart,int nLen) hiU_r="*ox
{ }wj*^>*
int n = -1; >,hJ5-9
try{ A 7DdUNR
oSavedFile.write(b,nStart,nLen); EX8]i,s|E
n = nLen; 5g/^wKhKG
} *M-.Vor?R
catch(IOException e) :M|bw{P*
{ \+L_'*&8
e.printStackTrace (); $`_(%tl
} YVu8/D@ o
gtjgC0
a;/4 ht
return n; _2f}WY3S
} o)S>x0|[
ecf<(Vl}
jcx/ZR
} >{Lfrc1
fp12-Hk ~
0Xk;X1Xl
/* HzbO#)Id-I
**SiteInfoBean.java s/Q}fW$ex
*/ ,EwJg69
package NetFox; ,ISq7*%F
{} vl^b
vbwEX6
public class SiteInfoBean { 5:n&G[Md
8Bhot,u'T
t*.v!
private String sSiteURL; //Site's URL PO)5L
private String sFilePath; //Saved File's Path &\!-d%||)
private String sFileName; //Saved File's Name {"{J*QH
private int nSplitter; //Count of Splited Downloading File ax7 M
Q&M(wnl5
z:<(b
public SiteInfoBean() ]p0m6}B
{//nSplitter的缺省值为5 9iS3.LCfX
//default value of nSplitter is 5 :Q\h'$C
this("","","",5); \I'A:~b)L
} Txoc
UK&E#i
=WDf [?ED
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {-17;M$
{ Z$WT ~V
sSiteURL= sURL; -U*XA
sFilePath = sPath; $V5Ol6@2
sFileName = sName; bdcuO)3
this.nSplitter = nSpiltter; YrZAy5\
n]8_]0{qi
zh50]tX
} G9VzVx#T#
@uH7GW}$g
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public String getSSiteURL() UI;!_C_
{ &V$'{
return sSiteURL; SB \ptF
} k5}i^^.
!uHI5k,f
*r9I 1W
public void setSSiteURL(String value) f#X`e'1
{ [;I.aT}R!;
sSiteURL = value; 2]4R`[#
} AvV.faa
1 !\pwd@{
`yC R.3+
public String getSFilePath() 9"V27"s
{ \t!+]v8f8
return sFilePath; L<Lu;KnY6
} _0vXujz
Wa[~)A
xX"?3%y>
public void setSFilePath(String value) 8Q6il-
{ 5#2vSq!H
sFilePath = value; YHKm{A ]
} {[Yv@CpN
9:=a FP
4AF"+L
public String getSFileName() n+!.0d}6
{ ~i &K,
return sFileName; 9Pem~<
} z1V0WDVm
|fzo$Bq
0p[$8SCJ
public void setSFileName(String value) {b#c0>.8-
{ *dKA/.g
sFileName = value; Tzk8y7$[
} }"cb^3
C]r$
Z;n}*^U
public int getNSplitter() g#70Sg*d
{ Pq_Il9
return nSplitter; kYR&t}jlCg
} D#k>.)g
^|sQkufo
WQK#&r*
public void setNSplitter(int nCount) |r /}r,t}
{ PGw"\-F
nSplitter = nCount; wCI.jGSBW
} liU=5BL
} *y0`P0V|8
|"@E"Za^
Cu|n?Uk
/* @:c 1+
**Utility.java _5X}&>>lhF
*/ 2ag]p
package NetFox; ,-{j.
T+~~w'v0
cAiIbh>c
public class Utility { JT:9"lmJz,
}'Z(J)Bg
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public Utility() ^#Wf
{ GUcuD^Fe
TVjY8L9'h
{QhvHV
} VK NCK
x[>A'.m@)
//线程睡眠 g^]Q*EBa
public static void sleep(int nSecond) q,*IR*B:a
{ N.&K"J
try{ |RpC0I
Thread.sleep(nSecond); Xz5=fj&
} c/hml4
catch(Exception e) YqDw*S{
{ /`'50Cj
e.printStackTrace (); L~yy;)]W
} r[?rwc^
} QOP*vH >J
nTHP~]
//日志 5Pr<%}[S^
public static void log(String sMsg) &FK=w]P
{ >PYe"
System.err.println(sMsg); !?+3jzG
} dyx4_!fO
oS`F Yy
>*_?^F_
public static void log(int sMsg) JN8k x;@
{ Bf-&[ 5N}
System.err.println(sMsg); a1}W2;W0]g
} qQom=x
} "Srp/g]a
2dq{n.cgs
UGN. ]#"#
/* PNKmI
**TestMethod.java fe Q%L
*/ B;-oa;m:E=
package NetFox; Y0b.utR&
mj,r@@k:=+
L8$7^muad
public class TestMethod { |fJ,+)_(
UtWoSFZ'o!
LD6fi
public TestMethod() \(z)]D
{ ///xx/weblogic60b2_win.exe \fKv+
try{ g=%W"v
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); I#,,h4C
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); V]<dh|x
SiteFileFetch fileFetch = new SiteFileFetch(bean); wHY;Y-(ZT
fileFetch.start(); r|#4+'
} FINM4<s)
catch(Exception e){e.printStackTrace ();} pkT a^I
I|PiZ1]2Y
#F9$"L1Hg
} `hfwZ*s
jt]+(sx
FIS-xpv$
public static void main(String[] args) `"bm Hs7
{ O+e8}Tmm
new TestMethod(); u )ld
} B]hZ4.B1
} }W YY5L8^
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