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)); t|!j2<e
} z=_Ef3`M
for(int i=0;i<nEndPos.length-1;i++) \,&co
{ .G(llA}
nEndPos = nStartPos[i+1]; f0<%&2ym
} ]oV{t<0a
nEndPos[nEndPos.length-1] = nFileLength; QgD g}\P
} P=+nB*hG
} )aao[_ZS
H_Kj7(=&>
?wF'<kEH
//启动子线程 |),'9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +sx 8t
for(int i=0;i<nStartPos.length;i++) J}@z_^|"mJ
{ VY"9?2?/
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qYf |Gv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7aYn0_NKp
nStartPos,nEndPos,i); MXiQ1x
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); C?=P
fileSplitterFetch.start(); _s$_Sa ;
} RZ7(J
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mVsIAC$}8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); drd/jH&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )r z+'|,
nEndPos = " + nFileLength); *"98L+
// fileSplitterFetch[nPos.length-1].start(); >,gvb5
b}wC|\s
k({\/t3i
//等待子线程结束 c.f"Gv
//int count = 0; { "xln/
//是否结束while循环 :nS;W
boolean breakWhile = false; }%`~T>/
)T66<UDK|
]I.n\2R]om
while(!bStop) d90Z,nex
{ 7GSV
write_nPos(); G #T<`>T
Utility.sleep(500); B_l{<
breakWhile = true; m6yIR6H
t"lyvI[
p,<&zHb>K
for(int i=0;i<nStartPos.length;i++) `)h6j)xiQ
{ J~iBB~x.
if(!fileSplitterFetch.bDownOver) p!V>XY'N^
{ 9F- )r'
breakWhile = false; 'snn~{hG
break; 5,;`$'?a%
} [;.`,/
} a7/-wk
if(breakWhile) \WrFqm#
break; C"qU-&*v
H:JLAK
W85@v2b
//count++; fiI $T:g.
//if(count>4) w[-Fm+A>
// siteStop(); e{9jn>\,a
} j! NO|&k
-/dEsgO
1?Aga,~k:a
System.err.println("文件下载结束！"); ph|ZG6:
} Ei3zBS?J)
catch(Exception e){e.printStackTrace ();} ia{c
} vNOH&ja-s
b*mKei
>x@P|\
//获得文件长度 lE ;jCN
public long getFileSize() XC3Kh^
{ '[(nmx'yVJ
int nFileLength = -1; M4LktR-[
try{ Gy Qm/I
URL url = new URL(siteInfoBean.getSSiteURL()); }Y1>(U
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w_4]xgS:
httpConnection.setRequestProperty("User-Agent","NetFox"); =AEz9d ciS
eL.7#SIr}
NOK/<_/
int responseCode=httpConnection.getResponseCode(); HFQR ;9]
if(responseCode>=400) rJ'I>Q~x6
{ o:dR5v
processErrorCode(responseCode); i=32KI(%
return -2; //-2 represent access is error V'2EPYB
} ^Ori| 4}'
l n}}5Q
"%QD{z_L
String sHeader; Y?r po
v)kEyX'K2d
OAZ#|U
for(int i=1;;i++) '69ZdP/xX
{ tNmy& nsA
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !sA_?2$
//Utility.log(in.readLine()); yWHiw<
sHeader=httpConnection.getHeaderFieldKey(i); @TA9V@?)
if(sHeader!=null) +|%Sx
{ kDYN>``biP
if(sHeader.equals("Content-Length")) W;Jx<-#1
{ `wTlyS3[
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &Rz, J]
break; npu6E;'l*
} V5GkP1L
} z&$/EP-
else agOk*wH5
break; i!dv0|_
} \H5Jk$*
} *sfD#Bi]
catch(IOException e){e.printStackTrace ();} N<_Ko+VF
catch(Exception e){e.printStackTrace ();} ` e{BId
} i)$n(A)K
gglQU"=g{
Utility.log(nFileLength); dj[apuiF
7/X"z=Q^|
Zq ot{s
return nFileLength; N\1/JW+
} I]J*BD#n.
/=#~
;+I4&VieK
//保存下载信息（文件指针位置） TQ1WVq }*
private void write_nPos() Lg`Jp&Kg
{ , Ut Hc]
try{ [ij,RE7,T
output = new DataOutputStream(new FileOutputStream(tmpFile)); r<L#q)]
output.writeInt(nStartPos.length); 22KI]$D#f
for(int i=0;i<nStartPos.length;i++) jV7&Y.$zF]
{ >n7["7HHk
// output.writeLong(nPos); z]$j7dp
output.writeLong(fileSplitterFetch.nStartPos); vh>{_ #
output.writeLong(fileSplitterFetch.nEndPos); {rkn q_;0
} 8R69q:
output.close(); af+}S9To
} 8h?X!2Nq
catch(IOException e){e.printStackTrace ();} 26:evid
catch(Exception e){e.printStackTrace ();} 5>ST"l_ca
} Ew^ @Aq
dNVv4{S
dTD5(}+J
//读取保存的下载信息（文件指针位置） qq+MBW*
private void read_nPos() }Pg' vJW
{ 0v"&G<J
try{ `:-J+<`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); n*qN29sx
int nCount = input.readInt(); abY0)t
nStartPos = new long[nCount]; cvAtwQ'
nEndPos = new long[nCount]; }w!ps{*
for(int i=0;i<nStartPos.length;i++) ":d*dl
{ jgvh[@uB?
nStartPos = input.readLong(); :?r*p>0$
nEndPos = input.readLong(); (@ea|Fd#4
} g^o_\hp
input.close(); `.k5v7!o
} -%uy63LbHF
catch(IOException e){e.printStackTrace ();} 5&4F,v[zp
catch(Exception e){e.printStackTrace ();} yCM{M
} <~%t$:
zw:/!MS
u2`xC4>c
private void processErrorCode(int nErrorCode) 8g5V,3_6
{ gB CC
System.err.println("Error Code : " + nErrorCode); {>.>7{7
} m(3);)d
4IGxI7~27#
T=? bdIl
//停止文件下载 .{N\<01
public void siteStop() )Ul&1UYA
{ uaQ&&5%%J
bStop = true; ,eELRzjl
for(int i=0;i<nStartPos.length;i++) uU+s!C9r
fileSplitterFetch.splitterStop(); O=O(3Pf>
-"Gl 4)
L/k40cEI^z
} WX*cICb5
} BpXEK.Xw
//负责部分文件的抓取 HRRngk#lV
**FileSplitterFetch.java f0F#Yi{fw
*/ VA]ZR+m
package NetFox; _XN~@5elrC
F|]rA*2u
9c5!\m1
import java.io.*; oBUh]sR{.
import java.net.*; &8Wlps`
x9*ys;~w
g@(30{
public class FileSplitterFetch extends Thread { CB@B.)E
|,fh)vO
x[m'FsR4
String sURL; //File URL T^.{9F]*S
long nStartPos; //File Snippet Start Position $wXih#7
long nEndPos; //File Snippet End Position fle0c^=
int nThreadID; //Thread's ID \2eFpy(
boolean bDownOver = false; //Downing is over 'O1.6*K
boolean bStop = false; //Stop identical )n7)}xy#z
FileAccessI fileAccessI = null; //File Access interface 'o8\`\'H!
n^Au*'
7dhn'TW
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException k <}I<Or
{ `]yKM0 Z
this.sURL = sURL; qi[(*bFK7
this.nStartPos = nStart; 'Fzuc^G(d
this.nEndPos = nEnd; 5k`e^ARf
nThreadID = id; s#Q_Gu
fileAccessI = new FileAccessI(sName,nStartPos);//定位 LsotgQ8
} F0: &>'}
bG1 ofsU
d:$G|<uA
public void run() zuj;T,R;
{ I! ITM<Z$l
while(nStartPos < nEndPos && !bStop) &.*T\3UO
{ }-@I#9
/kb$p8!C".
\1khyF'
try{ ]*h&hsS0
URL url = new URL(sURL); |x[$3R1@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r2)pAiTM*
httpConnection.setRequestProperty("User-Agent","NetFox"); bn|DRy
String sProperty = "bytes="+nStartPos+"-"; <lX:eR1
httpConnection.setRequestProperty("RANGE",sProperty); ][N) 2_^M
Utility.log(sProperty); /op/g]O}
9e76pP(
$@4e(Zrmo
InputStream input = httpConnection.getInputStream(); l2M/,@G
//logResponseHead(httpConnection); ;W4:#/~14
a:xgjUt&5
{N@Y<=+:
byte[] b = new byte[1024]; JbVi1?c
int nRead; 4jD\]Q="1
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %1@.7uTN
{ 0<"tl0p_
nStartPos += fileAccessI.write(b,0,nRead); :=B[yD!
//if(nThreadID == 1) nR#a)et
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a#6,#Q"
} A9.;>8!u
+"G(
/T4VJ{D
Utility.log("Thread " + nThreadID + " is over!"); }W)Mwu'W
bDownOver = true; _/8y1)I
//nPos = fileAccessI.write (b,0,nRead); (T`q++
} y#GCtkhi
catch(Exception e){e.printStackTrace ();} )[RpZpd`*
} D)RdOldr
} >R) F}
f@#w{W,3
l+'`BBh*]
//打印回应的头信息 AzW%+ LUD
public void logResponseHead(HttpURLConnection con) /!o1l\i=5
{ DD)mN) &T
for(int i=1;;i++) IFkvv1S`
{ ?RqTbT@~
String header=con.getHeaderFieldKey(i); aq$62>[
if(header!=null) Ld'EABM
//responseHeaders.put(header,httpConnection.getHeaderField(header)); F F(^:N
Utility.log(header+" : "+con.getHeaderField(header)); G0^V!0I&O
else AIf[W">\
break; FW5*_%J
} "&s9cO.H
} -!JlM@
" -<}C%C
tzP@3+.w
public void splitterStop() </2,2AV4q*
{ ]VmzKA|h+
bStop = true; +EQpD.
} YGi/]^Nba
23,%=U
o7hH9iY
} >zN" z)
6qY\7R2+
X~`.}
/* z;``g"dSw
**FileAccess.java [Ja(ArO3|[
*//文件访问(定位，写) ,$ho2R),Fn
package NetFox; U=_~{[/
import java.io.*; =t~+63)
F?!};~$=Z
fB@K'JQG
public class FileAccessI implements Serializable{ nA|gQibA
3/yt*cr
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -DbH6u3
RandomAccessFile oSavedFile; GC,vQ\
long nPos; ?T$*5d
zLE>kK
AD0ptHUBa
public FileAccessI() throws IOException #%9oQ6nO
{ *tIdp`xT/T
this("",0); m[//_TFf]
} UA1]o5K
jcT{ugpq
0m)-7@
public FileAccessI(String sName,long nPos) throws IOException "{,\]l&o
{ A?^A*e
oSavedFile = new RandomAccessFile(sName,"rw"); yd{Y}.
this.nPos = nPos; K*J4&5?/
oSavedFile.seek(nPos); dVjcK/T<
} MxFt;GgE8
`ja`#%^\u
#r78Ym'aI
public synchronized int write(byte[] b,int nStart,int nLen) }D&"z8mP
{ <yPq;#z(!
int n = -1; j=!(F`/
try{ 5e~ j
oSavedFile.write(b,nStart,nLen); Ac*B[ywA3
n = nLen; d;*OO xQV
} )M&I)In'
catch(IOException e) *B)Jv9
{ v^FV t
e.printStackTrace (); O?+tY y?
} mgJ]@s}9
;C7BoHB9
Rh05W_?Js
return n; 2^k^"<h5j
} [esX{6,i
uyS^W'fF
{7j6$.7J$&
} 3N)Ycf8
:G6 xJlE|
~_/<PIm
/* \Nh^Ig
**SiteInfoBean.java D]LFX/hlH
*/ rH [+/&w5
package NetFox; E.WNykF-
9Y!0>&o
c1Fru
public class SiteInfoBean { k:(e79
M+;!]tbc3
Q8M:7#ySji
private String sSiteURL; //Site's URL { c6DT
private String sFilePath; //Saved File's Path troy^H
private String sFileName; //Saved File's Name >qh>Qm8w
private int nSplitter; //Count of Splited Downloading File ]ouUv7\
)edU <1P
xC=3|,U
public SiteInfoBean() E@'CU9Fo
{//nSplitter的缺省值为5 d=.n|rS4 W
//default value of nSplitter is 5 jN5} 2 p*
this("","","",5); ;OT#V,}r
} 2:6Y83
!`d832
Hz;jJ&S
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &zg$H,@Qp
{ v3VLvh2)n
sSiteURL= sURL; \M3NasZ
sFilePath = sPath; b>>=d)R
sFileName = sName; A{u\8-u
this.nSplitter = nSpiltter; ?*MV ^IY
C4X{Ps\
}.Na{]<gh
} C7c|\T
oto wvm
zwniS6R1
public String getSSiteURL() k8t Na@H
{ 0W<nE[U
return sSiteURL; hD9'`SQ
} 4BUK5)B
iJynR [7
pyb}ha
public void setSSiteURL(String value) Pvb+
{ 2)j#O
sSiteURL = value; ^r?sgJ
} ]Pg?(lr6)
,~=z_G`R
9<0$mE^:
public String getSFilePath() l#5k8+s
{ \I o?ul}za
return sFilePath; Sv^'CpQ
} [>aoDJ
K:lT-*+S
sLpCWIy
public void setSFilePath(String value) U K]{]-
{ v#YS`];B
sFilePath = value; vSHIl"h
} "n2xn%t{
?#{2?%_
T\$^>@
public String getSFileName() LF3GVu,
{ >TJKH^7n
return sFileName; ^VLUZ
} |Bf:pG!
Q1>Op$>h
] l qFht
public void setSFileName(String value) <=GzK:4L
{ /{#_Um0.
sFileName = value; #I{Yf(2Z
} tRrY)eElS
w _6Y+
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public int getNSplitter() 6w`}+3
{ (Q p]0
return nSplitter; ;0_J7
} ~ dI&> CL
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;hRpAN
public void setNSplitter(int nCount) owS@dbO
{ C,e$g
nSplitter = nCount; 576-X_a,
} AB|VO4-?
} p(b1I+!
=g>7|?6>=
D 5wR?O
/* JV6U0$g_S
**Utility.java r :MaAT<
*/ @xM!:
package NetFox; d}B_ll#j-
:$Di.|l@7
,I:m*.q
public class Utility { sZP3xh[B
hZ/
`F`'b)
public Utility() Vh[o[ U
{ y2hFUq
hm} :Me$[)
"jN-Yd,z
} $(mdz)Cfy
=&g}Y
//线程睡眠 aD3F!Sn
public static void sleep(int nSecond) v]Q_
{ (,9cCnvmYU
try{ k)GuMw
Thread.sleep(nSecond); \fFy$
} iI Nu`>I
catch(Exception e) `h{mj|~
{ bqwW9D(
e.printStackTrace (); Mh/>qyS*2
} "Ohpb!J9
} x]01j4HJ
48NXj\L[y
//日志 6!D
public static void log(String sMsg) o0+BQ&A)s*
{ oX~$'/2v
System.err.println(sMsg); %-p{?=:K
} b0x0CMf
^9f`3~!#bc
6XCX#4'i%
public static void log(int sMsg) 7D_kkhN
{ &"6ktKrIg
System.err.println(sMsg); bFxJ|
} ex!wY
} Gy7x?
adPU)k_j:
Lj* =*V
/* !!X9mI|2|
**TestMethod.java teNQUIe-
*/ I=Dk'M
package NetFox; ymVd94L
4bjp*1*]
EKJ4_kkjM
public class TestMethod { E/-Kd!|"
W%ZU& YBc
l*MUDT@M8\
public TestMethod() W]MJ!4
{ ///xx/weblogic60b2_win.exe qvT+d l3#[
try{ }Fe{s;
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _<}5[(qu
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &>B>+}'
SiteFileFetch fileFetch = new SiteFileFetch(bean); )$N{(Cke2T
fileFetch.start(); =WRU<`\
} R6o<p<fTh
catch(Exception e){e.printStackTrace ();} 5 9HaTq
x9 L\"
. pEeR
} dnc!=Z89
)7mJ+d[
_q}%!#4
public static void main(String[] args) l0 :xQV`
{ y:zT1I@>
new TestMethod(); L"<Eov6
} A;HKR4p;8
} TUYl><F5v=
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