http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); sYq:2Wn>8Q
} yV~TfTJ
for(int i=0;i<nEndPos.length-1;i++) A`--*$8\
{ +CVB[r#hu
nEndPos = nStartPos[i+1]; M}! qH.W
} n^q%_60H
nEndPos[nEndPos.length-1] = nFileLength; qyBC1an5,
} lak,lDt]
} %[4u #G`
>akC
ur:8`+" (
//启动子线程 NXk~o!D
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; F pT$D
for(int i=0;i<nStartPos.length;i++) )Q 5 x%
{ 4]HW!J
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .L9g*q/}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), HUAbq }
nStartPos,nEndPos,i); 3(Ns1/;?,
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )oALB vX
fileSplitterFetch.start(); =]r2;014
} 3ey.r%n
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), cL<,]%SkE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); X }`o9]y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", xnC:?d
nEndPos = " + nFileLength); @Di!~e6
// fileSplitterFetch[nPos.length-1].start(); VKtlAfXy~
b^STegz
YQ@2p?4m
//等待子线程结束 h<Ct[46,S
//int count = 0; ? 'qyI^m@
//是否结束while循环 v, CWE
boolean breakWhile = false; xk
3RX9LJGX
TCFr-*x
while(!bStop) (q0vql
{ \11+~
write_nPos(); f|=u{6
Utility.sleep(500); QE8`nMf
breakWhile = true; L PS,\+
S&'?L0
aNn4j_V(
for(int i=0;i<nStartPos.length;i++) fP[S.7F+No
{ 2FW"uYA;6
if(!fileSplitterFetch.bDownOver) 2z.~K&+x
{ )QWhzY
breakWhile = false; joDqv,iW8
break; &"?99E>
} Dpwqg3,
} L|Xg4Z
if(breakWhile) hH9~.4+*`g
break; eZ$M#I=o
2">de/jS
`rXb:P7m{j
//count++; t 9t '9
//if(count>4) !MrQ-B(
// siteStop(); :.tL~% q
} Qcks:|5
Y]_$+Si:NK
1{5t.
System.err.println("文件下载结束！"); )+"5($~
} aM xd"cTzx
catch(Exception e){e.printStackTrace ();} ?K;l 5$?%
} u|Oc+qA(
Yg?BcY\
tUuARo7#
//获得文件长度 Y]*&\Ex"\
public long getFileSize() j/_&]6!
{ C0K: ffv;<
int nFileLength = -1; fdWqc_
try{ ^Vhl@
URL url = new URL(siteInfoBean.getSSiteURL()); CPL,QVO9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &S`g&
httpConnection.setRequestProperty("User-Agent","NetFox"); pGfGGY>i%
#?k</~s6M`
|d z2Drc
int responseCode=httpConnection.getResponseCode(); >&Oql9_
if(responseCode>=400) BzzZ.AH~
{ Vhh=GJ
processErrorCode(responseCode); k$ T
return -2; //-2 represent access is error ;Xa N
} AAs&P+;
o ^ \+Ua
Mvue>)g~>
String sHeader; Zxd*%v;
H] g=( %ok
0{uaSR
for(int i=1;;i++) sa&`CEa
{ O_ZYm{T[7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :8j7}'
//Utility.log(in.readLine()); p!8phS#iP
sHeader=httpConnection.getHeaderFieldKey(i); 3z, Ci$[
if(sHeader!=null) $qr6LIKGw
{ ZjMnGRP
if(sHeader.equals("Content-Length")) \@yJbhk
{ {;E6jw@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); A^p{Cq@E
break; #Q)r6V:
} |:&O!36
} y.I&x#(^
else :s&dn%5N"
break; V@T(%6<|
} v-SXPL]_^
} f>$RR_
catch(IOException e){e.printStackTrace ();} 3^nH>f-Y
catch(Exception e){e.printStackTrace ();} !4cY^4>o
^[r1Dk
qrp@
Utility.log(nFileLength); gC7Po
,~&HL7v
9PACXW0
return nFileLength; hdi0YL
} lZ7 $DGe
."=p\:^j*
b>8TH-1t~
//保存下载信息（文件指针位置） $2}#):`
private void write_nPos() JB].ht
{ @{q<"hT
try{ \o/eF&
output = new DataOutputStream(new FileOutputStream(tmpFile)); M2w'cdHk
output.writeInt(nStartPos.length); I#M>b:"te
for(int i=0;i<nStartPos.length;i++) Dw7Xy}I/
{ \>pm (gF
// output.writeLong(nPos); '2i !RT-
output.writeLong(fileSplitterFetch.nStartPos); ^9Cu?!xu0
output.writeLong(fileSplitterFetch.nEndPos); A7%/sMv
} 'Etq;^H
output.close(); :{ZwzJ
} Q!qD3<?5
catch(IOException e){e.printStackTrace ();} *Cf!p\7!
catch(Exception e){e.printStackTrace ();} T@i* F M
} NN=^4Xpc:
23i2yT
G`kz 0Vk
//读取保存的下载信息（文件指针位置） GF8wKx#J
private void read_nPos() __Ksn^I
{ "O0xh_Nr
try{ aA52Li
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); P_NF;v5v
int nCount = input.readInt(); T}=^D=
nStartPos = new long[nCount]; d)bsyZ;U
nEndPos = new long[nCount]; A9 g%>
for(int i=0;i<nStartPos.length;i++) E/a2b(,Tg
{ MjQju@
nStartPos = input.readLong(); pvUV5^B(M
nEndPos = input.readLong(); jq*`| m;Q
} j}",+Hv
input.close(); pvsa?z;rP
} M*ZN]9{^.
catch(IOException e){e.printStackTrace ();} Y 0Fq-H
catch(Exception e){e.printStackTrace ();} @`C'tfG/4
} (g/A uL
=t)qy5
eh<mJL%T
private void processErrorCode(int nErrorCode) z8awND
{ <\<o#Vq
System.err.println("Error Code : " + nErrorCode); C$PS@4'U
} 'UWkJ2:!
{9}CU~R
oC49c~`8
//停止文件下载 jF0"AA
public void siteStop() RPgz"-
{ J](NCD
bStop = true; @WS77d~S
for(int i=0;i<nStartPos.length;i++) 86 e13MF
fileSplitterFetch.splitterStop(); ;J TY#)Bh
e9RYk:O
[V:~j1{3
} QwWd"Of
} kt)Et
//负责部分文件的抓取 l7qW)<r
**FileSplitterFetch.java w/ rQOHV{
*/ y42Cg
package NetFox; jK]1X8
2{63:f1c`'
0jlM~H
import java.io.*; n.2:fk
import java.net.*; `}#rcDK
lMGO4U[z
m","m
public class FileSplitterFetch extends Thread { jL^@;"/XhC
czD"mI!
Y06^M?}
String sURL; //File URL {@)ZXg
long nStartPos; //File Snippet Start Position 4 O8ct,Y
long nEndPos; //File Snippet End Position $$NWN?H~
int nThreadID; //Thread's ID ~>u|7M$(
boolean bDownOver = false; //Downing is over I{g.V|+x
boolean bStop = false; //Stop identical ApeqbD5g&
FileAccessI fileAccessI = null; //File Access interface IoLi7NKw
s__xBY
b-VygLN
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +|obU9M
{ e!jy6t
this.sURL = sURL; [5?Dov^j3
this.nStartPos = nStart; MVzuE}
this.nEndPos = nEnd; f1ANziC;i
nThreadID = id; 196a~xNV
fileAccessI = new FileAccessI(sName,nStartPos);//定位 d'ZNp2L
} }`<&l
F/5G~17
D/."0 #q
public void run() vnvpb! @Q
{ z eT`kZ
while(nStartPos < nEndPos && !bStop) fF0i^E<
{ T3zovnR
%}9tU>?F#
"Bf8mEmp
try{ OLb s~ >VA
URL url = new URL(sURL); ?yef?JI$p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6[A\cs
httpConnection.setRequestProperty("User-Agent","NetFox"); mEd2f^R
String sProperty = "bytes="+nStartPos+"-"; 8eS(gKD
httpConnection.setRequestProperty("RANGE",sProperty); /o;L,mcx*
Utility.log(sProperty); W"vLCHTh
tjx8UgSi
hXjZ>n``
InputStream input = httpConnection.getInputStream(); Z\CvaX
//logResponseHead(httpConnection); Ie. on)
fasWb&~z
+112{v=!i
byte[] b = new byte[1024]; |z=`Ur@)
int nRead; ct3i^,i
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) AuXUD9-
{ z.cDbkf}
nStartPos += fileAccessI.write(b,0,nRead); CXuD%H]tx
//if(nThreadID == 1) Yn~fnI{
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c{/R?<
} eW(pP>@k,
[_)`G*X(N
6AAvsu:
Utility.log("Thread " + nThreadID + " is over!"); ;b0Q%TDh
bDownOver = true; ]LC4rS
//nPos = fileAccessI.write (b,0,nRead); hI86WP9*
} F0U %m
catch(Exception e){e.printStackTrace ();} lrv-[}}
} 0#J~@1Gf
} 1z6aMd6.
Z\IM~-
y 9]d{:9
//打印回应的头信息 C{J5:ak
public void logResponseHead(HttpURLConnection con) LBy`N_@
{ Qjj }k)
for(int i=1;;i++) -iDs:J4Iq
{ p2gdAJ
String header=con.getHeaderFieldKey(i); _'!?fA
if(header!=null) kuH%aM<R
//responseHeaders.put(header,httpConnection.getHeaderField(header)); QAV6{QShj
Utility.log(header+" : "+con.getHeaderField(header)); 2O=$[b3
else jV sH
break; dA hcA.
} $k\bP9
} vTK%8qoZ
k2D*`\ D
tw$EwNI[
public void splitterStop() J=3{<Xl
{ 4P3RRS
bStop = true; _s^tL2Pc
} h.vy SwF"j
uy<3B>3~.
utZI'5i
} MT>sRx#
l7VO8p]y[R
-w"I
/* `VwG]2 I
**FileAccess.java :g|.x
*//文件访问(定位，写) F-3=eKZ
package NetFox; *1dZs~_
import java.io.*; !}*vM@)1
1-p#}VX
#a}w&O";
public class FileAccessI implements Serializable{ H>/,Re
ompr})c
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7I[[S!((s
RandomAccessFile oSavedFile; aE07#
long nPos; jI8`trD
@:zC!dR)G
s1_Y~<yX
public FileAccessI() throws IOException $JOz7j(
{ ,5c7jZ5H
this("",0); ZvF#J_%gE5
} .@&FJYkLYi
}6[jJ`=gOx
_|C3\x1c
public FileAccessI(String sName,long nPos) throws IOException h/\v+xiF
{ y05!-G:Y\
oSavedFile = new RandomAccessFile(sName,"rw"); %_Vz0 D!7
this.nPos = nPos; HAO-|=c4
oSavedFile.seek(nPos); (>0`e8v!
} KcV"<9rE
z#Jw?K_
l5w^rj
public synchronized int write(byte[] b,int nStart,int nLen) |2^mCL.r
{ oqwW
int n = -1; !6|_`l>G,
try{ j4i$2ZT'
oSavedFile.write(b,nStart,nLen); OG<*&V
n = nLen; DL,R~
} $HQ~I?r{Hf
catch(IOException e) Q I";[
{ wBpt W2jA
e.printStackTrace (); : _Y^o
} \xS X'/G
h:pgN,W}
PNAvT$0LaZ
return n; rmw}Ui"
} 2Di~}*9&
ByjfPb#
]B(}^N>WH
} l#cVQ_^"
Kc]cJ`P4.
mdL T7
/* DH.`
**SiteInfoBean.java |E K6txRb
*/ RbUir185Y
package NetFox; +DSbr5"VlB
)q'dX+4=eL
w31O~Ve
public class SiteInfoBean { ^kNVQJiZyG
=Jl\^u%H(x
[UkcG9
private String sSiteURL; //Site's URL nycJZ}f:wP
private String sFilePath; //Saved File's Path jF6Q:`k
private String sFileName; //Saved File's Name mL1ZSX o!
private int nSplitter; //Count of Splited Downloading File 1R-0b{w[
1W*Qc_5 v1
6T4"m
public SiteInfoBean() iOa<=
{//nSplitter的缺省值为5 <6]Hj2
//default value of nSplitter is 5 Jy:@&c
this("","","",5); ZOqA8#\
} *><j(uz!
'*Y mYU
|8}y?kAC
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0D4 4
{ N''xdz3Z
sSiteURL= sURL; D`n<!"xg@$
sFilePath = sPath; d3EN0e+^
sFileName = sName; oa+'.b~
this.nSplitter = nSpiltter; <8%+-[(
\t{4pobo
&z3_N
} <2j$P Y9
b^i$2$9_
2FL_!;p;2E
public String getSSiteURL() 1;./e&%%
{ b?=r%D->w
return sSiteURL; Sy.%>$z
} )+G0m,n
K&._fG
bg3kGt0
public void setSSiteURL(String value) c5f57Z
{ fc:87ZR{K
sSiteURL = value; dh}"uM}a
} L9hL@
_j$V[=kdM/
X%!?\3S
public String getSFilePath() ?>=vKU5
{ lKQjG+YF
return sFilePath; LVP6vs
} tvJl-&'N
G|?V}pZ
'lC=k7@x
public void setSFilePath(String value) ( K-7z
{ 5-a^Frmg#"
sFilePath = value; mMZ=9 ?m
} WZA1nzRc
+7"UF) ~k
T8LvdzS
public String getSFileName() kVWrZ>McK
{ +CEt:KQ
return sFileName; #I ,c'Vj
} brE%/%!e
!`U #Pjp.
V[44aN
public void setSFileName(String value) 2DZ&g\|
{ YS9)%F=X
sFileName = value; Zjc/GO
} $ ga,$G
2Sy:wt
D_f:D^
public int getNSplitter() K=sk1<>)m
{ i+-=I+L3
return nSplitter; _Axw$oYS
} ]~m=b`o
m&*0<N
UBwYwm0
public void setNSplitter(int nCount) >Y3zO2Cr
{ z1e+Ob&
nSplitter = nCount; Mv%B#J
} >]bS"S
} dZJU>o'BG
{=^<yK2q
U$ZbBVa`~
/* @bFl8-
**Utility.java F>u/Lh!
*/ '~6l 6wi
package NetFox; SZgan
^3&-!<*
IgF#f%|Q
public class Utility { >vfLlYx
)/v`k>E
b!;WF
public Utility() k"`^vV[{F
{ (yeN> x}_
Iak06E
xUs1-O1i
} H#`&!p
j]9,yi
//线程睡眠 Bm^8"SSN
public static void sleep(int nSecond) P_N},Xry
{ \cAifU
try{ ,+g0#8?p^x
Thread.sleep(nSecond); n{F&GE="
} 4,6?sTuX
catch(Exception e) xO 1uHaL
{ Ac,bf 8C
e.printStackTrace (); PPtJ/ }\
} tUFXx\p
} "FfP&lF/
o, qBMo^.
//日志 P$A'WEO'
public static void log(String sMsg) |SsmVW$B|
{ 6<Zk%[7t
System.err.println(sMsg); ukXKUYNm8
} "k7C
=~j S
Bv=:F5hLG
public static void log(int sMsg) s[/)v:
{ /%^^hr
System.err.println(sMsg); <C7/b#4>\
} m3b?f B
} 1b"3]?
}l@7t&T|
Q"{Q]IT
/* V_Y2@4
**TestMethod.java MW.,}f
*/ cNuBWLG
package NetFox; '~Gk{'Nx"
{B\lk:"X
oth=#hfU^
public class TestMethod { hrnY0
V^p XbDRl
q/\Hh9`
public TestMethod() \E:l E/y
{ ///xx/weblogic60b2_win.exe 2W`<P2IA
try{ {&Sr<d5
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8J#TP7;
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); y +c 3#
SiteFileFetch fileFetch = new SiteFileFetch(bean); Os|F
fileFetch.start(); NIOWjhi[Jn
} AQz&u
catch(Exception e){e.printStackTrace ();} X=b]Whuv
rexy*Xv`2p
X1~ B
} >!2d77I
p[gq^5WuC
/H[!v:U
public static void main(String[] args) k;y5nXIlN
{ 3MFb\s&Fq
new TestMethod(); SQVyCxcX_
} 'x\{sv
} -qndBS
点击下载更多相关资料